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PZ - Odor Study Final Report
E IDIAN.- IDAHO NOW • e .ma VL Meridian, ID Wastewater Resource Recovery Facility Odor Study Phases 1 & 2 — FINAL Report �-ONAL April 2021 �� ��GISTER� r O � Prepared for: 11 3 The City of Meridian, ID ', q-Z 8-LOL l p W OF Prepared by: ��'? R 0 B$ �NVypONMt;�yr� Mountain WEB TER WATERWORKS ASSOCIATES,% Mountain Waterworks,Inc. Webster Environmental Associates, Inc. 1161 W River Street, Suite 130 13121 Eastpoint Park Blvd, Suite E Boise, ID 83702 Louisville, KY 40223 (208) 780-3990 (502) 253-3443 Meridian, ID Wastewater Resource Recovery Facility Odor Study Phases 1 & 2 - FINAL Report Table of Contents 1.0 Introduction 1.1 Background..................................................................................................1 1.2 Objectives ....................................................................................................1 1.3 Meridian WRRF Description.......................................................................2 2.0 Odor Generation and Characterization of Odors 2.1 Odor Generation...........................................................................................4 2.2 Odor Panel Procedures.................................................................................5 2.3 Reduced Sulfur Compound Test Procedures...............................................6 2.4 Hydrogen Sulfide Measurements.................................................................7 3.0 Description of Odor Testing and Modeling 3.1 Overview of Sampling & Testing Program.................................................8 3.2 Air Sampling Protocol...............................................................................10 3.3 Odor Dispersion Modeling ........................................................................14 3.3.1 Description of Modeling................................................................14 3.3.2 Modeling Output ...........................................................................15 3.3.3 Modeling Protocol .........................................................................16 4.0 Presentation and Discussion of Testing Results 4.1 Air Sampling Test Results.........................................................................16 4.2 Odor Emission Rates..................................................................................18 5.0 Odor Dispersion Modeling Results 5.1 Description of Modeling Scenarios ...........................................................20 5.2 Discussion of Modeling Results ................................................................20 6.0 Evaluation of Odor Control Alternatives 6.1 General.......................................................................................................24 6.2 Preliminary Odor Control System Design Criteria....................................25 6.3 Description of Odor Control Alternatives..................................................25 6.4 Discussion of Odor Control Scenario Modeling Results...........................31 7.0 Summary and Conclusions..................................................................32 8.0 Meridian WRRF Future Build-Out......................................................47 8.1 Future Build-Out Odor Dispersion Modeling............................................48 8.2 Discussion of Modeling Results ................................................................55 Meridian, ID Wastewater Resource Recovery Facility Odor Study Phases 1 & 2 - FINAL Report Table of Contents (Continued) Index of Tables Table 1 Odorous Sulfur Compounds in Wastewater.......................................................5 Table 2 Sampling & Testing Program.............................................................................9 Table 3 Air Testing Results Summary...........................................................................17 Table 4 Odor Emission Rates ........................................................................................19 Table 5 Peak DT Comparison Summary.......................................................................31 Table 6 Frequency Comparison Summary ....................................................................31 Table 7 2004 Theoretical Odor Values vs 2020 Field Odor Data .................................33 Table 8 Peak DT Comparison Summary.......................................................................46 Table 9 Frequency Comparison Summary ....................................................................46 Table 10 Peak DT Comparison Summary.......................................................................55 Table 11 Frequency Comparison Summary ....................................................................55 Index of Figures Figure 1 Meridian WRRF Site Plan.................................................................................3 Figure 2 Effects of pH on Distribution of Hydrogen Sulfide in Water............................7 Figure 3 Gas Sampling Train for Quiescent Surfaces ...................................................10 Figure 4 Sampling Locations................................................................................... 12-13 Figure 5 Meridian WRRF Existing Conditions Peak DT Contours ..............................22 Figure 6 Meridian WRRF Existing Conditions Frequency Contours............................23 Figure 7 Odor Control Scenario#1 Peak DT Contours.................................................26 Figure 8 Odor Control Scenario#1 Frequency Contours..............................................27 Figure 9 Odor Control Scenario#2 Peak DT Contours.................................................29 Figure 10 Odor Control Scenario#2 Frequency Contours..............................................30 Figure 11 2004 Odor Model Future 2023 Peak DT Contours.........................................34 Figure 12 Existing Conditions Peak DT Contours ..........................................................35 Figure 13 2004 Odor Model Future 2023 Frequency Contours (>7DT).........................36 Figure 14 Existing Conditions Frequency Contours (>20 DT) .......................................37 Figure 15 Boise Municipal Airport Windrose (2019)......................................................38 Figure 16 Nampa Municipal Airport Windrose (2010-18)..............................................39 Figure 17 Odor Control Scenario#3 Peak DT Contours.................................................42 Figure 18 Odor Control Scenario#3 Frequency Contours..............................................43 Figure 19 Odor Control Scenario#4 Peak DT Contours.................................................44 Figure 20 Odor Control Scenario#4 Frequency Contours..............................................45 Figure 21 Meridian WRRF Build-Out Capacity..............................................................47 Figure 22 Future Build-Out Peak DT Contours...............................................................49 Figure 23 Future Build-Out Frequency Contours (>20 DT)............................................50 Figure 24 Odor Control Scenario#5 Peak DT Contours.................................................51 Figure 25 Odor Control Scenario#5 Frequency Contours (>20 DT)..............................52 Figure 26 Odor Control Scenario#6 Peak DT Contours.................................................53 Figure 27 Odor Control Scenario#6 Frequency Contours (>20 DT)..............................54 Appendices A St. Croix Sensory, Inc. Odor Panel Results B ALS Environmental Reduced Sulfur Compound Testing Lab Results C Odalog Charts Meridian, ID Wastewater Resource Recovery Facility Odor Study Phases 1 & 2 — FINAL Report 1.0 Introduction 1.1 Background The City of Meridian has been growing rapidly in recent years with residential and commercial development moving closer to the City's Wastewater Resource Recovery Facility (WRRF), which was originally constructed on the outskirts of the city in a largely agricultural area. In 2004, an Odor Assessment was completed by the City to assist with confirming the allowable land uses (e.g. residential vs. commercial/industrial) set previously by the City in 2002 in the vicinity of the WRRF. The 2004 Assessment included identification and quantification of various odor sources,predicted theoretical odor values for the WRRF in 2023,development of mitigation strategies for various land uses (e.g. residential versus commercial/industrial), and preparation of estimated costs for recommended odor control improvements. To date, the land adjacent to the WRRF on the north, south, and west has seen limited development,but it is anticipated this will change in the coming years. The City has also undertaken multiple construction projects since the 2004 Assessment was completed to expand the facilities to accommodate the higher wastewater flows associated with a rapidly growing population. Consequently, the City has elected to update the 2004 Odor Assessment to reflect the current WRRF configuration and provide an improved understanding of current and estimated future odor emissions from the WRRF, and how these emissions could impact land use and development in the vicinity of the WRRF. The City rarely receives odor complaints associated with this facility but takes their odor control responsibilities very seriously and wants to be proactive. There have been four complaints in the past five years that were generally located to the east and southwest of the facility. Because of this they authorized this Odor Control Evaluation project (odor evaluation) with Mountain Waterworks. Webster Environmental Associates (WEA) was retained by Mountain Waterworks to perform the odor evaluation at the WRRF. The work was initiated in July of 2020. 1.2 Objectives The primary objectives of this odor evaluation are to: • Characterize the odors in terms of odor detection threshold (DT), HzS and reduced sulfur compound (RSC) concentrations • Use the odor data to conduct odor dispersion modeling to determine the Page I 1 WRRF's odor footprint within the surrounding community • Gather enough data to develop conceptual design criteria for future odor control improvements • Use the results of this testing program to develop conceptual long-term odor control alternatives 1.3 Meridian WRRF Description The Meridian WRRF utilizes a conventional aerated activated sludge process to remove BOD, nitrogen, and phosphorus from municipal wastewater. Major liquid- stream unit processes include: • Headworks facility with screening and grit removal • Primary clarification • Activated sludge process for nutrient removal • Secondary clarification • Tertiary filtration • UV disinfection • Sidestream RAS denitrification Major solid stream unit processes include: • Primary solids fermentation • Dissolved air flotation thickening • Mesophilic anaerobic digestion • Centrifuge dewatering • Centrate equalization and return to liquid process The facility, shown in Figure 1, was constructed in 1977, and since then has undergone an extensive series of process modifications necessary to increase treatment capacity and accommodate Meridian's rapidly growing population, which has reached approximately 100,000 residents. The facility is currently sized to treat a maximum month flow of 15 MGD, with provisions for additional treatment capacity to be added to accommodate future growth. Page 12 r PL • R' s 4p Figure 1 — Meridian WRRF Site Plan Page 3 2.0 Odor Generation and Characterization of Odors 2.1 Odor Generation Odor-producing substances found in domestic wastewater and sludge are small, relatively volatile molecules with a molecular weight of 30 to 150 pounds (lbs)per pound mole. Most of these substances result from the anaerobic decomposition of organic matter containing sulfur and nitrogen. Inorganic gases produced from domestic wastewater decomposition commonly include hydrogen sulfide (H2S), methyl mercaptan, dimethyl sulfide and other reduced sulfur compounds. H2S is the most commonly known and prevalent odorous gas associated with domestic wastewater collection and treatment systems. It is a colorless gas that is heavier than air, has a characteristic rotten egg odor, and is directly corrosive to metals and indirectly corrosive to concrete. H2S can be oxidized to sulfuric acid, which causes corrosion of concrete, metals and other materials. Many of the odors detected in wastewater collection and treatment systems result from the presence of sulfur-bearing compounds. A list of the most common malodorous sulfur-bearing compounds is shown in Table 1. The lower the molecular weight of a compound, the higher the volatility and potential for emission to the atmosphere. Substances of high molecular weight are usually not perceptibly odorous and are neither volatile nor soluble. It should be noted that organic chemicals of industrial origin, particularly solvents, are highly volatile as well as odorous and may contribute to overall odor emissions. The presence of turbulent or splashing conditions, such as overflow weirs in grit chambers and primary clarifiers increase the release of volatile odorous molecules. On the other hand, if the wastewater is aerobic and such odorous compounds are not present, such turbulence is beneficial because it promotes reaeration and the addition of dissolved oxygen, and thus prevents formation of odorous compounds associated with anaerobic conditions. Page 14 TABLE 1 -ODOROUS SULFUR COMPOUNDS IN WASTEWATER Odor Compound Formula Characteristic Odor Threshold (ppb) Hydrogen Sulfide F H2S Rotten eggs 0.4 Methyl Mercaptan CH3SH Decayed-cabbage 0.01 Dimethyl Sulfide CH3-S-CH3 Decayed-vegetables 1 Dimethyl Disulfide CH3-S-CH3-S Decayed-vegetables 2 Dimethyl Trisulfide C2H6S3 Pungent, sulfur-like 0.01 Carbon Disulfide CS2 Chloroform 10 Carbonyl Sulfide COS Unpleasant, sulfur-like 55 Odor Threshold—lowest concentration at which compound may be detected by a person with an average to above average sense of smell. ppb—parts per billion Reference:Design Manual: Odor and Corrosion Control in Sanitary Sewer Systems and Treatment Plants, USEPA/625/1-85/018,October 1985 Perceived odors are often complex mixtures of odorous compounds acting together to create "an odor"which may have characteristics significantly different from each of the individual components which is why odor panel testing is usually performed. Odor panel testing takes this blending of odorous compounds into account and provides the strength and dilute-ability of the odor. 2.2 Odor Panel Procedures Odor panels involve human panelists who participate in a series of scientifically controlled sensory tests. Common sensory properties used to characterize odors are: • Odor detectability reported as Detection Threshold(DT) • Odor recognition reported as Recognition Threshold(RT) DT values are used as inputs to the odor dispersion modeling, as discussed later in this report. A five to six-member odor panel consists of trained personnel who are scientifically screened to determine their smelling acuity to butanol. The odor panel testing, although subjective, is conducted under strictly controlled "clean" conditions to produce statistically valid results. The odor evaluations were conducted in accordance with ASTM Standard Practice E679-91 (Determination of Odor and Taste Thresholds by a Forced-Choice Page 15 Ascending Concentration Series of Limits) and E544-99 (Referencing Suprathreshold Odor Intensity). The dynamic dilution of odorous emissions is a physical process that occurs in the atmosphere down-wind of the odor source. An individual, or citizen from the community, sniffs the diluted odor. The number of dilutions needed to make the odor emission just detectable is known as the DT. The RT value is the dilution ratio at which the assessor first recognizes the odor's character. For example, an odor panel's response at DT may be"that smells"where the odor panel response at RT may be"that smells like a skunk". Odor Detectability and Recognition DT values reported from the odor panel refer to the number of dilutions of an odorous air sample required such that at least half the panel members are able to detect the presence of the odor. RT refers to the number of dilutions of an odorous air sample required before half the panel members are still able to characterize or recognize the odor. A high DT indicates a strong odor requiring many dilutions to render it undetectable. RT values are always less than DT values because it is easier to detect an odor than identify an odor. The relative magnitude of DT and RT values indicates the relative significance of odors from various odor sources. 2.3 Reduced Sulfur Compound Test Procedures Reduced sulfur compound testing is performed to specifically identify which compounds are present in the air and in what concentrations. This is important when selecting and sizing potential odor control alternatives. On this project, the air samples were collected in 3-liter Tedlar bags and then shipped to ALS Environmental for analysis. ALS Environmental analyzed the samples for the presence of RSC and other volatile sulfur compounds by direct injection Gas Chromatography/Flame Photometric Detection GC/FPD. The equipment used for this analysis was a Hewlett Packard 5890 Series I1 Gas Chromatograph/Hewlett Packard FPD Detector. The column used was a HP-VOC 3um film, 105 Meter x 0.53 mm ID. The sample volume injected into the GC/FPD ranged from 0.005 ml to 2.5 ml depending on sample concentrations. Purchased tank standards were used to calibrate for H2S and to determine other RSC concentrations. When H2S concentrations were too high to allow concentration estimates of other RSCs, or better detection limits were obtained by GUMS, their concentrations were estimated by the carbon disulfide response factor from the VOC calibration standard for the GUMS system. Page 16 2.4 Hydrogen Sulfide Measurements H2S can be measured in the field using H2S analyzers that provide instantaneous readings and/or continuous data logging. Since it is easy to measure, H2S is often used in wastewater situations as an odor indicator. In many cases, if the H2S is controlled,the odor problem will be eliminated. H2S is slightly heavier than air and moderately soluble in water. H2S dissolves in water and disassociates in accordance with the following reversible reaction: H2S H HS-+H+ The distribution of the above species is a function of pH, as shown graphically in Figure 2. The relative H2S concentration increases with decreasing pH. Only the dissolved sulfides can escape from the liquid(as H2S). Hydrogen sulfide is formed under anaerobic or septic (absence of oxygen) conditions. 100 0 80 20 1^' 2 � R y N 60 40 � 7 N N m a> O O tl> tl> fq �> � 0 C 40 60 c c N N U U G> a a 20 80 0 100 4 5 6 7 8 9 10 pH Figure 2 Effects of pH on Distribution of Hydrogen Sulfide in Water Page 7 During this evaluation, H2S was measured using an Arizona Instruments Jerome 631X H2S analyzer with a range of 0.003 to 50 parts per million (ppm). These measurements are used to identify or confirm odor (and H2S) sources at the plant. In addition, diurnal H2S concentrations were logged in several locations during the testing periods using OdaLog H2S analyzers. Odalogs are less accurate than the Jerome but are capable of measuring higher concentrations and can be deployed in areas with harsh conditions over extended periods of time. The Odalogs were calibrated prior to use on this project and the data was downloaded to a computer and plotted. All of the test results are presented in Section 4 of this report. 3.0 Description of Odor Testing and Modeling 3.1 Overview of Sampling & Testing Program The comprehensive sampling and testing program,shown in Table 2,began on July 21, 2020. On that date, a kickoff meeting was held to discuss the objectives of the study and to give the plant staff an overview of the sampling that would be conducted. Odalog(H2S) monitors were also installed in pre-determined locations. A total of fourteen (14) samples were collected for odor panel analysis and twelve (12) samples were collected for RSC analysis during the sampling program on August 4 — 5, 2020. The odor samples were packaged and shipped by overnight express to St. Croix Sensory, Inc. in Stillwater, MN for odor panel analyses on the following day. The RSC samples were packaged and shipped overnight to ALS Environmental in Simi Valley, CA for RSC analyses. The weather conditions on the days of sampling were as follows: August 4t' Sunny with a high of 93°F August 5ch Sunny with a high of 98°F These weather conditions are representative of warm, dry weather which is typically the worst-case conditions for odor emissions. Page 18 Table 2 - Sampling & Testing Program Testing Type Odor RSC H2S H2S Airflow Location Sample' Sample2 Continuous3 Instantaneous4 Measurements Old Headworks Influent Junction Box X X X X Influent Pump Station X X X X Headworks Dumpster Room (Biofilter Inlet) X X X Centrifuge Exhaust X X X X X Centrate Tanks X X X X Primary Clarifier#5 X X X X New Aeration Basin Anaerobic Zone X X X Biosolids Drying Pile X X X New Aeration Basin Aerobic Zone X X Daft#2 Exhaust X X X X Old Secondary Clarifier X X X New Secondary Clarifier X X X Headworks Biofilter Outlet X X RAS/WAS Tank X X X X Totals 14 12 7 14 1 Notes: 1. Odor Samples- Grab samples were shipped overnight to St. Croix Sensory, Inc. for odor panel analysis as per ASTM International E679. 2. RSC Samples- Grab samples were shipped overnight to ALS Environmental for gas chromatograph analysis of Reduced Sulfur Compounds (RSCs). 3. H2S Continuous- OdaLog instruments were deployed to measure and record hydrogen sulfide (1-12S) concentrations continually. 4. H2S Instantaneous- H2S analyzers were used to measure and record hydrogen sulfide (H2S) concentrations instantaneously. 5. Airflow Measurement-Airflow were measured using a hot wire anenometer. Page 9 3.2 Air Sampling Protocol Air samples were collected in chemically inert Tedlar bags with a polypropylene access valve. Samples for Odor panel analysis were collected in 10-liter bags and samples for RSC analysis were 77 collected in 3-liter bags. Air samples from ` non-aerated processes, such as the secondary clarifiers, were collected using a surface emission flux chamber (an EPA approved device used to measure emissions from surfaces), a vacuum chamber, and two small battery-operated Teflon pumps connected by Tygon tubing to draw air from the flux chamber and to add carbon filtered sweep air as shown in Figure 3. New Tygon tubing was used for every source to prevent contamination of the tubing. Air samples from point sources, such as the odor control system inlet and exhaust points, do not require the use of a flux chamber but the Tygon tubing, vacuum chamber and pump were still used on those point sources to prevent contamination of the air samples. k 2.5 Lhnin Carbon -- -,� .- Filter � et Flow at i Urnin Flux Chamber Teflon Tedlar Pump Ambient d Bag Air Odor Source Teflon Vacuum Chamber Pump Figure 3 - Gas Sampling Train for quiescent surfaces In all cases, the sample container was filled with the sample and then purged to "condition" the container and remove any background container odor prior to collection of the final sample for odor panel analysis. Page 110 The air samples were collected from each source and shipped to the laboratories via overnight express courier where they were analyzed the following day. The flux chamber is an enclosed chamber used to isolate a surface and is set-up as a continuously stirred reactor. Sweep air is added to the chamber at a controlled, fixed rate of 5 liters per minute (L/min). The emission rate for odors is calculated by knowing the sweep air flow rate, concentration and the surface area exposed to the chamber. The operation of the flux chamber involves: (1) Identifying the test area and placing the chamber (2) Initiating the sweep air(clean, filtered air) flow rate to the flux chamber (3) Operating the chamber for four residence times before collecting samples (4) Collecting exhaust gas at 2.5 L/m for analysis (5) Decontaminating the chamber for the next test area The specific sizes of the flux chamber are: Chamber surface area= 0.13 square meters (m) Chamber volume= 0.03 cubic meters (m3) Odor emissions for each source are quantified with the flux chamber technique, using the following calculation: ER=Y * Q * (A2/Al) * C where: ER=Emission Rate of compound or odor (DT * airflow for odor) Y=concentration of compound from air in the flux chamber(ppm or DT) Q = sweep air flow rate of filtered air into flux chamber(L/min) Ai = surface area enclosed by the flux chamber(ft) A2 = surface area of odor source (ft) C = correction factor for conversion from metric to English units Figure 4 shows pictures of the locations where samples were collected at the Meridian WRRF. Page 111 sill�+ta6�' Old Headworks Influent Junction Box Influent Pump Station Headworks Dumpster Room Centrifuge Exhaust I ME Centrate Tanks Primary Clarifier #5 Figure 4 - Sampling Locations Page 12 New Aeration Basin Anaerobic Zone Biosolids Drying Pile � j■ New Aeration Basin Surface DAFT#2 Exhaust `ow, Secondary Clarifiers RAS/WAS Tank Figure 4 - Sampling Locations (Continued) Page 13 3.3 Odor Dispersion Modeling 3.3.1 Description of Modeling Odor dispersion modeling has been used as a reliable and cost-effective approach for predicting off-site odor impacts from odor sources and evaluating odor mitigation alternatives. The odor dispersion model is a computer program designed to predict what impact an odor source, or group of odor sources, will have on an area based on a number of factors that are input into the program. The primary inputs include: • Odor emission rates from individual odor sources • Odor source dimensions and characteristics • Historic meteorological data • Local terrain data The software used to complete the modeling is Breeze AERMOD v9.0.0.23 Pro Plus Version developed by Trinity Consultants Inc. AERMOD is the preferred EPA model for simulating the impacts of emissions from a variety of sources where a near field(less than 50 km) condition exists. AERMOD is a comprehensive, steady state Gaussian plume dispersion model that is commonly used for odor assessments as it assumes direct transport from a source to a receptor for every hour of meteorological data, which is designed to yield a conservative result in terms of odor impacts in the community surrounding the facility. The model is used to predict and simulate the dilution of odors from the sources, measured in terms of Detection Threshold (DT) for the maximum hourly value of the year throughout the study area. The modeling in this study uses actual meteorological data from the Boise Municipal Airport weather station and the most recent full year surface and mixing height data available, obtained from Trinity Consultants, Inc. The data includes the actual hourly meteorological data (wind speed, wind direction,temperature, cloud cover,ceiling height, and mixing height)from every hour of the year. The information input into the model for this study was Odor Emission Rates (OER) for each odor control system exhaust stack; exhaust stack locations, discharge heights and size; the on-site meteorological conditions from the Boise airport weather station; and digital terrain data. The OER is the Detection Threshold(DT) at the source multiplied by the air flow rate. Page 114 3.3.2 Modeling Output The model output predicts the highest DT level, estimated over the area of analysis. The resulting peak DT levels are shown graphically on odor contour plots. Essentially,the model predicts the number of dilutions in the atmosphere in the downwind DT, or the detection threshold of the odor. In this study, the hourly average DT levels at particular receptor points were converted to peak DT levels by applying a multiplier to account for short exposure to odors (60 seconds). The peak DT is more relevant for odors, since the odor plume meanders and is very transient. Perceived odor complaints are generally related to peak odor levels,as opposed to an hourly average odor level. Another modeling routine also predicts the frequency of odor events for the areas surrounding the plant. In other words, it predicts the number of times per year odors may be detectable for at least a one-minute period at any point in the study area. For example, a person standing at a point where a frequency of 100 is predicted would be expected to experience an odor that exceeds the selected odor detection threshold 100 times per year. In this study, an odor detection threshold of twenty (20) DT has been selected by the City of Meridian. The industry standard for an odor detection threshold is seven(7)DT,but as noted in the 2004 Odor Study which looked at a wide range of detection thresholds set by various cities across the nation it can be as high as twenty(20) DT. It is important to understand that an odor with a detection threshold of seven dilutions or less may not be detected because it could be overwhelmed by other natural odors in the area such as grass, trees, soil and flowers, or it may not be detectable at all. Because of this,the City has chosen to use 20 DT as the baseline for detectable odors in this study. Many of the cities that were surveyed in the 2004 Odor Study set odor threshold goals of not exceeding 20 DT for 100 hours or less in a year. 3.3.3 Modeling Protocol The modeling scenarios were completed with the following modeling protocol settings: • Peak-to-mean multiplier of: (Averaging Period / Peak Duration) 0.5 = (60 min / 1 min) 0.5 = 7.75, based on one hour averaging period,one minute average peak duration, and 0.5 power factor. • Elevated terrain option • Digital local terrain data • 2019 surface and mixing height meteorological data,collected from the Boise airport meteorological station (nearest available relevant meteorological data) Page 115 • Threshold of 20 DT used for the odor frequency modeling (value was selected by the City) 4.0 Presentation and Discussion of Testing Results 4.1 Air Sampling Test Results A summary of the air testing results for the Meridian WRRF is provided in Table 3. The data includes H2S concentrations,DT,RT, and RSC concentrations from the locations where this sampling was performed. The complete odor panel and RSC test reports from St. Croix Sensory and ALS Environmental are included in Appendix A and Appendix B, respectively. The OdaLog charts are included in Appendix C. The Centrifuge Exhaust Stack, Primary Clarifier Effluent Launders, the Anaerobic and Anoxic Zones within the Aeration Basins had higher DT values. The Old Headworks Influent Junction Box, the Biosolids Drying Pile, the Primary Clarifier Quiescent Surfaces and the Influent Pump Station all had moderate DT levels. The rest of the sources that were tested had very low odor levels. Page 116 Table 3-Air Testing Results Summary H2S Field Measurements ��� Odor Panel Testing RSC Testing(2) Continuous Continuous Detection Recognition Inst. Peak Avg. Threshold Threshold H2S MM DMS DMDS Location (ppm) (ppm) (ppm) (DT) (RT) (ppb) (ppb) (ppb) (ppb) Old Headworks Influent Juction Box 1.20 28 3.4 9,200 5,900 150 14 15 5.1 Influent Pump Station 1.30 46 15.0 5,900 2,900 1,100 110 23 7.3 Headworks Dumpster Room(Biofilter Inlet) 0.01 NM NM 380 210 60 0 0 0.0 Centrifuge Exhaust >50 E E 430,000 240,000 89,000 38 0 0.0 Centrate Tanks 0.34 14 0.6 490 270 57 9 0 4.7 Primary Clarifier#5 4.40 167 7.8 40,000 24,000 4,000 160 22 8.3 New Aeration Basin Anaerobic Zone 5.90 NM NM 47,000 33,000 16,000 650 45 26 Biosolids Drying Pile 0.36 NM NM 9,900 5,000 25 57 73 900 Aeration Basin Surface 0.002 NM NM 180 100 NM NM NM NM DAFT#2 Exhaust 0.011 3 0.4 150 75 0.0 0 0 0.0 Existing Secondary Clarifiers#3 0.013 NM NM 180 110 8.8 0 0 0.0 New Secondary Clarifiers#6 0.015 NM NM 170 75 6.9 0 0 0.0 Headworks Biofilter Outlet 0.007 NM NM 100 55 NM NM NM NM RAS/WAS Tank 1.10 0 0 4,600 2,700 510 8.8 41 3.1 Notes: (1)1-12S Field Measurements were measured and recorded as follows: Instantaneous(Inst.)concentrations were measured directly from each odor sample as they were collected using a Jerome 631x. Continous concentrations were measured and recorded at specific locations using continuous data loggers from July 21 to August 5,2020. (2)Laboratory Reduced Sulfur Compound(RSC)results are reported in parts-per-billion(ppb).Values left blank indicate that the resulting measurements were below the detection limits of the laboratory instrumentation. RSC Abbr. (odor threshold, ppb): 1-12S=hydrogen sulfide(0.5), MM=methyl mercaptan(0.5), DMS=dimethyl sulfide(0.1), DMDS=dimethyl disulfide(2.2), WITS= dimethyl trisulfide(0.01) (3)NM= Not Measured (4)E= Instrument error; no data Page 117 4.2 Odor Emission Rates The potential for off-site odors from the Meridian WRRF was evaluated in this report by calculating "Odor Emission Rates" (OER), which is the product of DT multiplied by exhaust air flow rate. The OER data is also used in the air dispersion modeling to predict off-site odors from individual sources as well as combined sources. The following methods were used to determine the air exhaust flow rates (cfm) from the sampled sources at the WRRF. 1. Rated capacity or measured air flow rate of blowers or exhaust fans. 2. Estimate of the surface air emissions based on surface area of the source and the amount of sweep air added to the flux chamber. (See formula in Section 3). Table 4 presents the results of the odor emission rate calculations for all odor sources evaluated during the odor testing. The data includes the surface area of the source, air flow rate, DT, resulting odor emission rate (OER), and the percentage of the total OER for each of the processes evaluated during the testing. The OER inventory may be used as a preliminary method for considering the potential for off-site odors from the individual processes,prior to odor dispersion modeling. The OER takes into account the odor strength at the source (DT) and the amount of air flow exhausting the odorous air into the atmosphere. The onsite testing did not include testing of the aeration basin anoxic zones. Table 4 shows an assumed DT value for the anoxic zones based on years of testing data at other wastewater treatment plants. Due to the presence of nitrates in the anoxic zones acting as an oxidizing agent, sulfides and odors typically have much lower concentrations than the anaerobic zones. WEA averaged DT values from testing anoxic zones in previous odor studies at similar wastewater treatment plants to determine a value for the anoxic zones at the Meridian WRRF. Page 118 Table 4 - Odor Emission Rates Surface Air Flow Detection Odor Emission Area Rate (t) Threshold Rate Percentage Location (ft) (cfm) (DT) (DR x cfm) of Total Centrifuge Exhaust 0.3 100 430,000 43,000,000 38.70% Primary Clarifier#3-6 Effluent Launders 5,332 676 40,000 27,040,000 24.33% Primary Clarifier#3-6 Quiescent Surface 20,104 2,544 6,000 15,264,000 13.74% New Aeration Basin Anaerobic Zones 1,564 198 47,000 9,306,000 8.37% Existing Aeration Basin Anaerobic Zones 1,564 198 47,000 9,306,000 8.37% New Aeration Basin Anoxic Zones 3,944 499 5,000 2,495,000 2.25% Existing Aeration Basin Anoxic Zones 3,944 499 5,000 2,495,000 2.25% RASMAS Tank 1,800 228 4,600 1,048,800 0.94% Existing Secondary Clarifiers#3-5 23,550 2,435 180 438,300 0.39% New Secondary Clarifiers#6-7 15,700 2,435 170 413,950 0.37% DAFT#1 or#2 Exhaust(') 9 1,500 150 225,000 0.20% Old Headworks Influent Juction Box 80 10 9,200 92,000 0.08% Total Plant Sources = 111,124,050 100% Notes: (1)Only one DAFT is in operation at a time so model only considers exhaust from one DAFT. Page 19 The centrifuge exhaust was found to have the highest OER of all the odorous sources that were tested, which accounted for approximately 38.8% of the total OER from the plant. The four primary clarifier effluent launders were found to have the second highest OER during the testing period, accounting for a total of about 24.4% of the total OER or 6.1% each. The four primary clarifier quiescent surfaces make up approximately 13.8% of the total OER or 3.45% each. To reduce the number of samples and overall cost of the odor study at the Meridian WRRF,WEA was instructed to only collect air samples from one primary clarifier and assume that the other three are identical. The aeration basin anaerobic zones were found to account for approximately 16.8% of the total OER from the WRRF. The processes listed in the paragraph above account for approximately 93.8% of the total OER from the WRRF. The rest of the sources that were tested have very low odor levels and as a result, have minimal impact on the offsite odor footprint from the plant. 5.0 Odor Dispersion Modeling Results See Section 3.3.2 for explanation of Peak DT and Frequency figures. 5.1 Description of Modeling Scenario Existing Conditions This scenario simulates the off-site odor impact of all significant existing processes at the Meridian WRRF, as tested during the testing period. All significant existing plant processes, operating in "normal" mode, are simulated in this modeling scenario, including: • Influent Junction Box • Primary Clarifiers • Aeration Basins Anaerobic Zones • Aeration Basins Anoxic Zones • RAS/WAS Tank • DAFT#2 • Centrifuge Exhaust Vent • Existing Secondary Clarifiers #3-5 • New Secondary Clarifiers #6-7 5.2 Discussion of Modeling Results Figures 5&6 show the Peak DT and Odor Frequency contour maps for the existing conditions scenario. Page 120 The model predicts Peak DT (worst case) values reaching 50 — 100 DT in the neighborhoods directly north of the plant and 60 DT at W.McMillan Rd.The model predicts odors from the plant could be detectable (> 20 DT) during approximately 100—200 hours per year in these locations. The model predicts Peak DT (worst case) values reaching 40 — 50 DT at N. Black Cat Rd. to the west of the plant. The model predicts odors from the plant could be detectable (>20 DT) during up to 50 hours per year in these areas. The model predicts Peak DT (worst case) values reaching 50 — 100 DT in the neighborhoods across W. Ustick Rd. to the south of the plant. The model predicts odors from the plant could be detectable (> 20 DT) during approximately 50 - 100 hours per year in this area. The model predicts Peak DT (worst case) values reaching 60 — 100 DT in the neighborhoods across N. Ten Mile Rd. to the east of the plant. The model predicts odors from the plant could be detectable (>20 DT) during up to 50 - 100 hours per year in this area. Page 121 • s� �o `�o �o McMillan Rd o 75 00 3 100 4a 50 c7 � ri `' tro W tick Rd ' __��='G ..,,..x. 100 &o Alo �:. AID 40 WSJ W M illan Rd 'j PIM 13 00 lit 1100 47 n � �►��Jyrryy_ . � " ■ � I pit IIII� �}�d .,�"� { L' W Ustick Rd .4 Tx � � 1 1 ■ ■ I I 6.0 Evaluation of Odor Control Alternatives 6.1 General The most effective way to prevent off-site odor emissions at the City of Meridian WRRF is to capture and treat the foul air in an air treatment system. There are numerous odor control technologies available for consideration such as chemical scrubbing, carbon adsorption,biological oxidation, and thermal oxidizers. Thermal oxidation is rarely a cost-effective option due to its high energy demand. This technology is typically only used when treating odors from solids processing facilities and when an abundance of digester gas is available as free fuel. Chemical scrubbing utilizes chemicals to oxidize odorous compounds. This technology can be effective and has a small footprint. However, this technology requires the storage and handling of hazardous chemicals which poses a safety concern to workers. Additionally, chemical scrubbers can be costly to operate. Carbon adsorption is a broad term that typically refers to a dry media system that adsorbs("catches") odorous compounds within the media pore structure. There are many types of media that can be utilized in a carbon adsorber depending on the inlet concentrations. Carbon adsorption systems are typically most cost effective when H2S concentrations are low to moderate. Biological oxidation is the utilization of microorganisms to remove odorous compounds from the foul airstream. Biological oxidation can be accomplished through bioscrubbers or biofilters. Bioscrubbers utilize synthetic media and are typically housed inside of vertical, cylindrical Fiberglass Reinforced Plastic (FRP) vessels. Bioscrubbers are most efficient when inlet H2S is in the moderate to high range. Biofilters can utilize organic or inorganic media. Organic media biofilters utilize wood media and are typically constructed in concrete structures in the ground or utilize an existing, abandoned tank. Inorganic media biofilters utilize coated rock media and can be constructed in concrete tanks in the ground or in horizontal, rectangular FRP vessels. Organic media is much less expensive than inorganic media but must be changed out more frequently (typically every 3-4 years for organic media and every 10 years for inorganic media).Both provide excellent odor removal. For this study, we are conducting a high-level evaluation of odor mitigation alternatives for the highest odor sources at the WRRF, according to Table 4. These sources will include the centrifuge exhaust and the primary clarifiers. Based on the data that was collected during the onsite testing portion of the study from Phase 1, Page 124 the odor mitigation scenarios that will be presented and modeled will include biological treatment and carbon(dry media) adsorption. 6.2 Preliminary Odor Control System Design Criteria In order to adequately size odor control systems for the odor sources being evaluated for this study and have a basis for the odor dispersion model for each scenario, airflows from each source were calculated or measured during the onsite testing, along with anticipated odor concentrations. Design airflow rates are based on air changes per hour(ACHR)within a covered space. Centrifuge Exhaust Odor Control System • Airflow— 100 cfm(as measured in existing exhaust stack) • Inlet Odor Concentration—430,000 DT • Odor Removal Efficiency—95% • Outlet Odor Concentration—21,500 DT Primary Clarifier Effluent Weir • Airflow— 1,200 cfm per system, or 600 cfm per clarifier (6 ACHR within headspace of covered primary clarifier effluent launders) • Inlet Odor Concentration—40,000 DT • Odor Removal Efficiency—90% • Outlet Odor Concentration—4,000 DT 6.3 Description of Odor Control Alternatives A total of two(2)odor control scenarios were developed and evaluated with respect to overall impact to the WRRFs odor footprint using the odor dispersion model. This section provides a description of each scenario and odor dispersion modeling results. Odor Control Scenario #1: For Odor Control Scenario #1, WEA is only evaluating the impact of treating the centrifuge exhaust.According Table 4 this source accounts for approximately 38% of the total odor emissions from the WRRF. Due to the high levels of 1-12S and odors that were measured in the centrifuge exhaust, WEA is evaluating the impact that installing a 2-stage odor control system will have on the WRRFs overall odor footprint. The 2-stage odor control system would be a 100 cfin bioscrubber followed by carbon adsorption. Based on WEAs extensive design experience and testing data for similar systems, it is assumed that there will be a 95% removal of odors. Page 125 20 McMillan p �. 100 :t 0 ! 150 00.. IL III"" If 150 75 7 0 ' Wu ckR . 40 so 60 �. 3040 } r Jo RO 1 � � W Mc illan Rd _ 5010 ,_.-.�• 0 4 y 14, 1500 { yyy T V CIL W UStick Rd `tea/ `!�• .� i ' ..� + �" +�,�+�*,} ,wyt � 'a1:*r fit. �� `_ � .�.�}�• {i �� � 'w.{ "�y�}� - r s rl 7 1 R 1 � 1 � � 1 1 1 1 1 1 � � Odor Control Scenario #2: For Odor Control Scenario #2, WEA is evaluating the impact of treating the centrifuge exhaust and the effluent launders of the four (4) primary clarifiers. According Table 4 these two sources account for approximately 63% of the total odor emissions from the WRRF. Due to the high levels of H2S that was measured coming off of the surface of the primary clarifier effluent launders, WEA believes that a biological odor control system would provide the best treatment for this source. The levels of 112S are too high to consider carbon adsorption, as the media would be spent very rapidly and be cost-prohibitive to maintain. Because of this, WEA will evaluate the impact of installing a 1,200 cfm biological odor control system to treat the effluent surface of primary clarifier 3 & 4 and a second 1,200 cfm biological odor control system to treat the effluent surface of primary clarifier 5 & 6. Based on WEAs extensive design experience and testing data for similar systems, it is assumed that there will be a 90% removal of odors for the biological odor control systems. For this scenario, the 2-stage odor control system described in scenario #1, which achieves 95% removal of odors, for the centrifuge exhaust will also be included in the model. Figure 9 & Figure 10 show how treating the air from the centrifuge exhaust and primary clarifier effluent launders will impact the results of the odor dispersion model. Page 128 20S w M c d 40 39 1 SO ron 0 200 . T Xy At `gj 1?0 R 40 o o IN U Rd AO 2 4 J .wT." • r `fir � �' ' �?p .,�+� ��� .rya• " 15 • 1 40 W McMillan Rd "'�� •`y. i�.�� � Y�" gip!'"p...._..:�,:-.�. `4 uW64-v ry ,rT -'.IF A :_ a :f�• a 700 W Ustick Rd -•-� hd {r �l. Aye L . -16 } k OL, ,fir .y it • ri .. l i 11 6.4 Discussion of Odor Control Scenario Modeling Results One way to evaluate and compare the modeling results of the two odor control scenarios versus the existing conditions is to pick two random points on the aerials and show what the Peak DT and Frequency values are at those locations for each scenario. In this case,a blue star and a red star have been shown at the same location on all models. The Peak DT values at those two locations are shown in Table 5 and the Frequency values are shown in Table 6. Table 5 - Peak DT Comparison Summary Model Scenario Blue Star Location Red Star Location Existing Conditions 100 90 Odor Control Scenario #1 75 75 Odor Control Scenario #2 50 50 Table 6 - Frequency Comparison Summary Model Scenario Blue Star Location Red Star Location Existing Conditions 200 50 Odor Control Scenario #1 200 50 Odor Control Scenario #2 100 <50 For Odor Control Scenario #1, the model is predicting the impact of treating the most odorous source, according to Table 4, at the WRRF. According to Table 4, the centrifuge exhaust accounts for approximately 38%of the odor emissions from the WRRF. The improvement seen in the Peak DT values offsite is roughly 20-25% if you refer to the Peak DT values at the blue star and red star locations on the existing conditions model versus the Odor Control Scenario #1 model. However, closer to the WRRF, there really isn't that much change. Although the centrifuge exhaust accounts for about 38% of the overall odor emissions from the plant, a significant factor in the model is the height of a point source above ground level, and the outputs from the model are based on the perspective of a"receptor"located at ground level. The higher an emission source is located above the ground surface, the more dispersion, mixing and dilution with the surrounding ambient air is provided. A ground-level receptor is consequently less likely to notice odors emitted from a tall stack than they would be if the emission source was located at ground level. The model results show that while odor control of the centrifuge exhaust would provide a modest reduction on the peak odors that are intermittently detectable at ground level, it would not have a discernible impact on the number of hours per year that plant odors exceed 20 DT. This result indicates that the 35-foot stack height is functioning as intended to dilute odors below the detection threshold at ground level. Page131 For Odor Control Scenario #2, the model is predicting what type of impact there will be on the WRRFs odor footprint if the centrifuge exhaust and the primary clarifier effluent launders are treated. According to Table 4, these two sources account for approximately 63% of the total odors at the WRRF. This scenario reduces the Peak DT values at the blue star and red star locations by approximately 50% and 45%, respectively. Closer to the boundary of the WRRF,where there is a Peak DT value of 500 in the existing conditions model, the Peak DT value is 200 in this odor control scenario. This results in a 67% reduction in odors directly outside of the property boundary, which is completely different from how odor control scenario #1 impacted the offsite odor footprint. This is occurring because the primary clarifier effluent launders are an area source located at ground level. Because of this, the odors do not disperse upwards like they do with the centrifuge exhaust. Instead, they "crawl" across the ground and treating this type of source makes a much bigger impact near the property boundary. When comparing the Frequency values of the existing conditions model and the Odor Control Scenario #2 model at the blue star and red star locations, there is a noticeable reduction of odor occurrences of 20 DT or greater. In the blue star location under existing conditions, the model predicts odors of 20 DT or greater to occur for a total of 200 hours through the course of the year. In the red star location, the model predicts odors of 20 DT or greater to be detectable during 50 hours out of the entire year. In these same locations, the model predicts the Frequency of odors to be 100 at the blue star location and less than 50 at the red star location. 7.0 Summary & Conclusions It is WEA's understanding that this odor study is going to be used to help guide the City's decisions on land use designations for the land that surrounds the WRRF. With that as the focal point of how this study would be used, WEA and Mountain Waterworks recommended the study be conducted under worst-case conditions. For an odor study at a wastewater treatment plant,worst-case conditions typically occur during the driest,hottest time of the year because sulfide generation in wastewater increases as wastewater temperatures increase. Sulfide generation and HzS, one of the main odorous compounds found at wastewater treatment plants, are directly related. For this study, WEA feels like nearly worst-case conditions were captured. The odor study conducted in 2004 by Carollo and WEA was intended to predict future odors at the WRRF once planned future expansions had occurred. Since the 2004 study, the plant has added a new headworks,two(2)primary clarifiers,four(4)additional aeration basins and two (2) secondary clarifiers. This study is intended to update the 2004 odor projections with the changes that have occurred at the WRRF. The 2004 odor study used theoretical/assumed odor values for the treatment processes and the 2020 odor study uses field data that was collected in August 2020 and analyzed in labs. Table 7 shows how the theoretical values used in the 2004 study compare to the field data collected in this study. Page132 Table 7-2004 Theoretical Odor Values vs.2020 Field Odor Data 2004 Study Theoretical 2020 Odor Panel Odor Values Testing Detection Detection Threshold Threshold Location (DT) (DT) Old Headworks Influent Juction Box 4,000 9,200 Influent Pump Station N/A 5,900 Centrifuge Exhaust 500 430,000 Centrate Tanks 2,000 490 Primary Clarifier Quiescent Surface 1,800 6,000 Primary Clarifier Effluent Launders 4,000 40,000 Aeration Basin Anaerobic Zones 1,000 47,000 Aeration Basin Anoxic Zones 1,000 5,000 Daft#2 Exhaust 1,800 150 Secondary Clarifiers 50 180 RAS/WAS Tank N/A 4,600 Figure 11 & Figure 12 below shows a side-by-side comparison of the Peak DT Contours from the 2004 odor model and the 2020 odor model. Page 133 ° - � M c r 'an 113 .;. a ]ant 2023 :. . .. b ' T It.0LLrS . y - Al TIP S Hsu � a° tog � o TS ISD ] CH k9� + fill � �•a' � ri a �-`o �•• . Figure 11 —2004 Odor Model Future 2023 Peak DT Contours Page 34 00 'SO MEMO McMillan Rd : Do ISO •, 160 40 CQU lob tick Rd 00 40 40 r H D 71:, Figure 13 &Figure 14 below shows a side-by-side comparison of the Frequency contours from the 2004 odor model and the 2020 odor model. Please note that these two figures do not represent an"apples to apples"comparison because the Frequencies in Figure 13 from the 2004 study are based on odors exceeding 7 DT, while the Frequencies in Figure 14 from the 2020 study are based on odors exceeding 20 DT. Although 7 DT is an industry standard for odor dispersion modeling,in WEA's experience an odor of 7 DT can be nearly undetectable above naturally occurring and other background odors. Therefore, a baseline of 20 DT was used for the odor dispersion modeling in this study. eridian WWI UIftk IL 41 7 r �Lm-P ►. - la Figure 13—2004 Odor Model Future 2023 Frequency Contours (>7 DT) Page 36 50 W M Milian Rd r LIN ; cep all 0 f� ' ,,Y r •Y.. y, y 00 so hW Ustik Ind 4 � L JJlL 3 4-6 To verify the results of the odor dispersion model, a 2019 Windrose, shown in Figure 15, was obtained from the Boise Municipal Airport Meteorological Station to show the prevailing wind direction throughout the course of the year. The Boise Municipal Airport Meteorological Station was the closest location for which meteorological data was available for input into the odor dispersion model. The windrose shows the prevailing wind in this location is predominantly from the southeast and northwest which directly correlates with what the model is showing. For example, in Figure 14 you can see that the odor frequency contours to the northwest of the WRRF extend much further away from the facility than those to the southeast, or any other direction from the WRRF, indicating that odors of 20 DT or more are occurring more often in that direction. Another example is that you can see that the contour line that represents 200 hours of odors exceeding 20 DT per year to the northwest of the WRRF is much further away from the property boundary of the WRRF than the same contour line to the southeast. N NW - -- NE 7.0% 6.0% 5.0% 4.0% 3.0% 2.0% 1.0% % W Calm E 14.8% 5W SE Summary obs count: 9700 Calm values are a 2.0 mph Arrows indicate wind direction. Missing: 338 Generated: 10 Nov 2020 Avg Speed: 7.3 mph 5 Wind Speed[mph] 2-5 � 5-7 7-10 � 10-15 15-20 i 20+ Figure 15— Boise Municipal Airport Windrose (2019) Page 38 To further justify the wind and weather data that was obtained from the Boise Municipal Airport Weather Station, the City obtained a windrose from the Nampa Municipal Airport Weather Station.The windrose from the Nampa Weather Municipal Airport Station,shown in Figure 16 below, is very comparable to the windrose that was obtained from the Boise Municipal Airport Weather Station. Both figures show that the prevailing wind directions in this area are mainly from the southeast and northwest. All Weather Wind Rose COVERAGE'10.5 KTS 99-106I 13 KTS 99-65%- 16 KTS 99.93%—20 KTS 99.98% OBSERVATIONS:216.423 TIME PERI00:2010-2018 DATA SOURCE:ON—SITE AWOS N �o sn 27 Q + Zr h + + } 1] -5 YONO COVERAGE: + 3 W + -g 20 KNOTS 99.98R + + 16 KNOTS M93R / '1 13 KNOTS 99-65% + .l 59.5 KNOTS 99.10% •t + + z + t .5 + + 5 + t T 3• + + d S}y ? + 20 1 tg° J S Figure 16—Nampa Municipal Airport Windrose (2010-18) The weather data from the Boise Municipal Airport Weather Station is the best available weather data for the odor dispersion model unless the City prefers to take the time and incur the expenses associated with setting up their own weather station at the WRRF. If the City chooses to do this,the weather station will need to be capable of collecting a minimum of 1-year of wind direction, wind speed, temperature and cloud cover data. The 2004 model, which was used to predict odors in 2023 at the WRRF and not existing conditions, compared to the 2020 model outputs show very similar results when comparing the Peak DT models even though the WRRF has nearly doubled in terms of treatment processes. An example would be comparing the Peak DT contour line at the Ten Mile Rd. and Ustick Rd. intersection. The 2004 study shows a Peak DT of 75 at this location and the 2020 study shows a peak of 100. The main differences in what was predicted and what is actually happening are the difference in odor values for sources such as the centrifuge exhaust,the primary clarifiers and the aeration basin anaerobic zones. The actual field data Page139 for these sources and the theoretical values used in the 2004 study differ substantially. The 2020 study is theoretically more accurate as it utilized actual odor sampling instead of predicted values. Table 7 above shows the differences. It should be noted that in 2004, there was no odor control at the WRRF. A new biofilter has recently been installed and treats air from the new headworks facility. This system is performing very well, as the measured outlet odors were only 100 DT, which is very low. Additionally, since the 2004 study a bioscrubber has been installed on the fermentation process. The bioscrubber was not tested during the 2020 odor study. The addition of effective odor control systems such as these will help offset the high odor emissions from sources such as the centrifuge exhaust, primary clarifier effluent launders and aeration basin anaerobic zones. As a result of this study, the City can clearly see that the majority of the odors impacting the land around the WRRF are coming from the centrifuge exhaust, the primary clarifiers and the aeration basin anaerobic zones by referencing Table 4 and the odor emission rates. Based on the alternatives that the City requested be evaluated for this study, odor control scenario #2 provides the best reduction of odors outside of the boundaries of the WRRF because it is capturing and treating the two biggest emission sources at the facility. Odor control scenario #1 only provides a modest reduction in Peak odors and Frequencies because the centrifuge exhaust is a point source that is being dispersed out of an elevated exhaust stack and the odors are getting good dispersion and have less of an impact outside of the boundaries of the WRRF than what was originally thought in Phase 1 of this study. Sources such as the primary clarifiers are overpowering the odor contributions from the centrifuge exhaust, which largely reduces the impact of treating the centrifuge exhaust. However,this source is still emitting a large quantity of odors, as indicated in Table 4, and there will likely be certain weather conditions where the centrifuge exhaust has a much greater impact on the offsite odors. The "area" sources, such as the primary clarifier effluent launders, have a much bigger impact on the odor footprint from the WRRF because these sources are at ground level and do not have an exhaust stack. Instead,the odors are"crawling" across the ground and have a much bigger impact on the offsite odors outside the boundaries of the WRRF than a similar point source. Because of this, odor control scenario #2 (Figures 9 & 10), which treats the centrifuge exhaust and the primary clarifier effluent launders provides a theoretical odor mitigation that greatly reduces the Peak odors and the Frequency in which an odor occurrence (>20 DT) happens. With this scenario, an estimated 63% of the total odor emissions would be captured and treated, effectively reducing the Peak offsite odors and the Frequency at which they occur by approximately 50%. To put the Frequencies for odor control scenario#2 into perspective, the blue star location in Figure 10 shows that an odor has the potential to occur 100 hours out of the year in this location, which represents roughly 1% of the year. Page 140 Additionally, it should be noted that the biosolids stockpile was tested but is not included in the odor dispersion model. Because the stockpile of biosolids varies from being non- existent all the way to having several piles stored, there is no way to effectively include this source in the model. However,the source was tested for odors during the onsite testing and the biosolids had an odor value of 9,900 DT, as indicated in Table 3. When a pile of biosolids is present, it is likely that it may be contributing to the off-site odors and could be another future area for odor mitigation strategies. If the City chooses to investigate further mitigation of the odors coming from the WRRF, the aeration basin anaerobic zones and primary clarifier quiescent surfaces, which are "area" sources, have high odor emissions and are big contributors to the offsite odors. Collectively, the anaerobic zones account for nearly 17% of the total odor emissions from the WRRF and the primary clarifier quiescent surfaces account for roughly 13%of the total odor emissions. WEA put together two additional modeling scenarios, odor control scenario #3 and #4, that include capturing and treating the primary clarifier quiescent surfaces and the anaerobic zones of the aeration basins to visually show the impact that these sources have on the offsite odors. Figure 17&18 show what the impact would be if the City chose to cover the entire primary clarifier surfaces. Odor control scenario #3 would be treating the centrifuge exhaust, the primary clarifier effluent launders and the primary clarifier quiescent surfaces. Page 141 � . • . 7p , _ • McMillan o 7s - � 110 3() 40 {' .16 - � ■ r . 170 50 fp _ W Ustick R ,• 20 30 {i 1 J t C. (D W McMillan Rd �46Re Pi,, all — • zi AL Y. it { 6i i .� �`� k Jar��M.' `_ r _ 'I 1�i�.� +'i•'i ` �„ � i.F F 1� �! I.I.I rµ 4 �.,1 4 .�• ���` w� �i Figures 19 & 20 show what the impact would be if the City chose to cover and treat the entire primary clarifier surfaces and the anerobic zones of the aeration basins. Odor control scenario#4 would be treating the centrifuge exhaust,the primary clarifier effluent launders, primary clarifier quiescent surfaces and the aeration basin anaerobic zones. N :14 '7t t{ d - � Ae0000-00 a 1 0 fr w cm 30 1 t 1 54 IL 2 r � w } Figure 19—Odor Control Scenario#4 Centrifuge Exhaust, Primary Clarifier Effluent Launders, Primary Clarifier Quiescent Surfaces and Aeration Basin Anaerobic Zones Peak DT Contours Page 44 McMillan Rd =- - sY •, t It oft% pi ..I r: _i71 r I III L' �11��,.�+• 1� _ w .�kd .1 t �� �i•J W Ustick Rd "ftIII-.. — - : AN R w rr ,,ll 4• ! - •iY d' ry 4 'n'4 y. �L ' -a.'il•f[R► n ti� }�- .•�+1 • To compare the results of odor control scenarios #3 and #4 to the results of the existing conditions and odor control scenarios #1 and #2, the blue star and red star reference locations are used on the figures above the same as they were used on previous figures in the report. Values at these locations are compared for all scenarios in Table 8 & 9. Table 8 - Peak DT Comparison Summary Blue Star Red Star Model Scenario Location Location Existing Conditions 100 90 Odor Control Scenario #1 75 75 Odor Control Scenario #2 50 50 Odor Control Scenario #3 30 35 Odor Control Scenario #4 10 10 Table 9 - Frequency Comparison Summary Blue Star Red Star Model Scenario Location Location Existing Conditions 200 50 Odor Control Scenario #1 200 50 Odor Control Scenario #2 100 <50 Odor Control Scenario #3 <50 <50 Odor Control Scenario #4 <50 <50 Odor control scenario#3 and#4 further justify that the"area"sources at the WRRF are the biggest contributors to the offsite odors. Based on the results of all of the scenarios that were looked at as part of this study, WEA would recommend first mitigating the "area" sources. It is very clear that treating the primary clarifiers entirely, odor control scenario #3,has a big impact on the odor footprint of the WRRF. Even though primary clarifiers are very large and have operational and maintenance needs, there are very effective ways to cover these surfaces while still allowing operation and maintenance needs to be achieved. WEA has designed several systems that cover primary clarifiers entirely to capture and treat odors while still meeting the needs of operations and maintenance staff. As shown in odor control scenario #4, by treating the aeration basin anaerobic zones in addition to the primary clarifiers, the City will achieve even greater odor control. The aeration basin anaerobic zones are the last big "area" source contributor at the site. By treating the primary clarifiers and the aeration basin anaerobic zones, the City would achieve odor control that greatly reduces the frequency at which an odor occurrence (>20 DT)happens outside the boundaries of the WRRF. Figure 20 shows that the model predicts an odor of 20 DT to be detected only up to 50 hours in a given year outside the boundaries of the WRRF. Page 146 WEA would recommend a detailed investigation that looks at the cost to achieve each odor control scenario presented in this report so the City can weigh the cost/benefit of implementing each scenario. By performing this detailed investigation, the City can visually see the potential reduction in offsite odors versus the cost to achieve it. 8.0 Meridian WRRF Future Build-Out In 2015 Brown & Caldwell developed a Facility Plan for the Meridian WRRF. As part of that project, Brown & Caldwell developed a site plan of the WRRF that is representative of the full potential build-out capacity of the facility. The future build-out capacity of the WRRF includes an additional four(4)primary clarifiers,three (3)aeration basin trains and four(4)secondary clarifiers. Figure 21 shows the Brown&Caldwell site plan representing the WRRFs future build-out capacity. -•� Cvea, Pmrv7rdrefMa �. Red Aroeea Af png i Pump S�tieru P.ryd.. 5ehds Fivrd.rxf Cnpse�r • Pnk ter6vy Ynfetm�e.M..1 YaMuw- Elec,nc�l ,•Pam•^-Y C4rdrr 5 y. _ 2•Prvnay C✓a�r5 ' 2 - 3Aen6en9�,s S-& e-Pmwy SkNip PA F Sw.asxauaM�trl r• .: _ 6-Poem Sundby Gwwwaa{2Qe OY1 • 'r _ ti`t � T-nemSeM1 8lb Bumm .r ,� v .�/ - •4fr B�S.w.darxChrter7 i ,�k �• ,P RASPS 1 I-FA51wR5 diaiind and PS 1I MwfC.aRci llpgrade •'�' f L r 1 1} I pwr Clu L., u r w - ' -P CimFier '!` a 15-Pwmy UNAH 9 T '! '� -i s � lrr Prrury tlurfiec 10 ' r _ 1&Aeraew Rae.ru IS16 r�'`• '�` _ 6 VA ,'F A,enaen Caen,r,to r ri �n (e LJ 1 ,�f ! 4p8i 2u S.wrd-y U"*18 � - `121.S.�ndtiT CkrrTMr s 1 - ]I 9 r p� PqF B. / 01Hfl+nv G.w'SR�:OA: 9..c•..:::ntW werr i-��rrw e'h e!a� `.a LdMU e.gwN.i4l'N 9 A9 ;OC Vp ... FodpN L��77l177BB��11 ���y�� •wrx Figure 21 —Meridian WRRF Build-Out Capacity Because the future build-out at the WRRF will add so many new processes that could potentially add to the odor footprint of the WRRF, the City tasked WEA with completing additional modeling to predict what those conditions will look like. Page 147 8.1 Future Build-Out Odor Dispersion Modeling This scenario simulates the off-site odor impact of all significant existing processes and future processes at the Meridian WRRF. The modeling will use odor data from the onsite testing that was completed in 2020. It will be assumed that all future processes will have the same footprint and odors (i.e. the future primary clarifiers will have an odor value of 6,000 DT for the quiescent surfaces). All significant plant processes, operating in "normal" mode, are simulated in this modeling scenario, including: • Influent Junction Box • Existing Primary Clarifiers • Existing Aeration Basins Anaerobic Zones • Existing Aeration Basins Anoxic Zones • RAS/WAS Tank • DAFT#2 • Centrifuge Exhaust Vent • Existing Secondary Clarifiers • Future Primary Clarifiers • Future Aeration Basins Anaerobic Zones • Future Aeration Basins Anoxic Zones • Future Secondary Clarifiers Figure 22 & 23 show the Peak DT and Frequency contours, respectively, of the WRRF at future build-out with no odor control in place. Page 148 M d iso Ago �. 00%N+2100160 - z z Ave n 75 0 ' W Ustick Rd - 0 + ` jjFF . 16 . ASo + z z .. Aw ' 7.5 77 VV Mc Ian } ff w + 0 � � r I - *f 0 r s r i * I # AN 4. so AMC Pe efl f 5' ## I R - ti� r 1 "I r ti Figure 23 —Future Build-Out Frequency Contours (>20 DT) For comparing what the future build-out will look like to the existing conditions, WEA evaluated two odor control scenarios for the future build-out conditions that are similar to odor control scenarios #3 and #4 that were evaluated for existing conditions. Odor control scenario #5 includes treating the centrifuge exhaust, the primary clarifier effluent launders and the primary clarifier quiescent surfaces. Page150 Figure 24 shows the Peak DT contours when odor control scenario #5 is implemented at the Meridian WRRF. Figure 25 shows the Frequency contours for this odor control scenario. 'f `0 30 -d 50 30- 41 t x ' t . 0 r� t ►0 _ d .0 so 40 PT r 1 1 Figure 24—Odor Control Scenario #5 Centrifuge Exhaust,Primary Clarifier Effluent Launders and Primary Clarifier Quiescent Surfaces Peak DT Contours Page 51 1 M illan Rd p 1 p I ' IF a 200 .. IL 10p0) R� to W Us 'ck Rd i -- - - nr. i,.Jr,�.,,► - Jllllllllllllll _ �* '' �,� • ��" .1. Y.yt �' * • T L ` r_ t •,1 'jhrf 1 y 1++�-- �I� � �# �tii{ M'�IF�+ • �` i i� � # I'F r r rr� �,t�'wi�,'r • � � 14 1 / PM Ffffwmm al I I1 1 1 , Figures 26 & 27 show what the impact would be if the City chose to cover and treat the entire primary clarifier surfaces and the anerobic zones of the aeration basins. Odor control scenario#6 would be treating the centrifuge exhaust,the primary clarifier effluent launders, primary clarifier quiescent surfaces and the aeration basin anaerobic zones. � w 20 W&UMillan 00 lb f 30 r� 15. r r 1177R �11• a } t to • { Figure 26—Odor Control Scenario#6 Centrifuge Exhaust, Primary Clarifier Effluent Launders, Primary Clarifier Quiescent Surfaces and Aeration Basin Anaerobic Zones Peak DT Contours Page 53 WMcMillanP.d ■ S *.I a, 1 A�L-�_ x Iro r I A �rI 00 w - +�LI - W-1 stick d F5 At le 5 • • J 1 �• t � � � •� t i i 1 1 i 11 1 8.2 Discussion of Modeling Results Similar to how the modeling results for each scenario in previous sections were compared, the same two random points on the contour maps are used to determine the impact of the future build-out of the WRRF and the effectiveness of implementing the different odor control scenarios. Tables 10 & 11 show the odor values at the two randomly selected points on the contour maps for the Future Build-Out Conditions and for odor control scenarios #5 and#6. Table 10 - Peak DT Comparison Summary Model Scenario Blue Star Location Red Star Location Ddsting Conditions 100 90 Future Build-Out Conditions 200 250 Odor Control Scenario #5 75 100 Odor Control Scenario #6 30 30 Table 11 - Frequency Comparison Summary Model Scenario Blue Star Location Red Star Location Ddsting Conditions 200 50 Future Build-Out Conditions 400 100 Odor Control Scenario #5 175 75 Odor Control Scenario #6 <50 <50 The results of the modeling show that when the WRRF reaches its full build-out capacity, the Peak DT odor values at the two reference points will double or more. Similarly, the Frequency at which an odor will reach 20 DT at the reference point locations will double. As it was discussed previously, the area sources are the biggest offsite odor contributors at the Meridian WRRF. With the future expansion of the WRRF, there will be four (4) additional primary clarifiers, three (3) additional aeration basin trains and four (4) additional secondary clarifiers. All of these sources are area sources and have a big impact on the odor footprint of the WRRF. Because odor control scenarios #3 and#4 focus heavily on capturing and treating air from the area sources, WEA has used the same approach for odor control scenarios #5 and #6. For odor control scenario #5, the centrifuge exhaust, the primary clarifier effluent launders and the primary clarifier quiescent surfaces would be treated. For this scenario,the Peak DT odor value at the blue star location was decreased from 200 DT to 75 DT and from 250 DT to 100 DT at the red star location. That is an estimated reduction of 60% or more in peak odors at these locations. For the Frequency values, at the blue star location the frequency at which an odor will reach 20 DT was reduced from 400 hours per year to 175 hours per Page 155 year. At the red star location, the frequency dropped from 100 hours per year to 75 hours per year. Odor control scenario 46 used the same approach as odor control scenario #4. For odor control scenario #6, the centrifuge exhaust, the primary clarifier effluent launders, the primary clarifier quiescent surfaces and the aeration basin anaerobic zones are being treated. For this scenario at the WRRFs full build-out capacity, the Peak DT odor value at the blue star location was decreased from 200 DT to 30 DT. At the red start location, the Peak value was reduced from 250 DT with no odor control to less than 30 DT. The result is more than 85% reduction in Peak odors at the two reference point locations. The Frequency at which an odor reaches 20 DT or greater at the blue star location was reduced from 400 hours per year to less than 50 hours per year. At the red star location, the Frequency was reduced from 100 hours per year to less than 50 times per year. Page156 Appendix A St. Croix Sensory Inc. Odor Panel Results (Izq � C-16-1 I06-1 I-'If I-G St. Croix Sensory, Inc. Odor Evaluation Report Report Number: 2021802 Project Name: Meridian WRRF Study Samples Collected: 8/4/20 Samples Received: 8/5/20 Samples Evaluated: 8/5/20 Report Prepared For: Webster Environmental Associates,Inc. 13121 Eastpoint Park Blvd, Ste. E Louisville, KY 40223 Report Prepared By: St.Croix Sensory,Inc. 1150 Stillwater Boulevard North Stillwater, MN 55082 U.S.A 1-800-879-9231 stcroix@fivesenses.com Data jrw�"At�- Release Authorization: Reviewed and Approved: Michelle Harty Charles M. McGinley, P.E. Laboratory Manager Technical Director St.Croix Sensory is ISO/IEC 17025:2005 Accredited Perry Johnson Laboratory Accreditation,Inc. Accreditation No.:81047 Certificate No.:L18-374 Initial Accreditation Date:19 May 2014 Odor Evaluation Report C1�1-III St. Croix Sensory,Inc. Client: Webster Environmental Associates,Inc. Report Number: 2021802 Project Name: Meridian WRRF Study Samples Evaluated: 8/5/20 # Field No. Sample Description DT RT I HT DR Comments I 1 1 Old Headworks Influent 9,200 5,900 --- --- --- 2 2 Influent PS 5,900 2,900 --- --- --- 3 3 Headworks Biofilter Inlet 380 210 --- --- --- Field sample diluted 10:1 for threshold 4 4 Centrifuge Exhaust 430,000 240,000 --- --- --- evaluation. 5 5 Centrate Tanks 490 270 --- --- --- 6 6 Primary Clarifier 40,000 24,000 --- --- --- 7 7 New Aeration Basins 47,000 33,000 --- --- --- 8 8 Biosolids Pile 9,900 5,000 --- --- --- Odor Detection Threshold Testing(Evaluations)conducted in compliance with and under all conditions specified or required by ASTM E679 and EN13725 unless noted in report"Comments"column. The Client Chain of Custody(COC)attached to the Odor Evaluation Report provides information that may include sampling location(s),methods,and/or environmental conditions during sampling. Client,designated agents,and/or reviewers provide interpretation of results based on sampling conditions. DT-Detection Threshold as determined by ASTM E679 and EN13725. The Practical Detection Limit(PDL)of DT is 12,based on the nominal lowest dilution presentation ratio of 8.Result is dimensionless dilution ratio at which half the assessors detect the diluted air as different from the blank air. Odor Units (OU)or Odor Units per cubic meters(OU/m3)are commonly used as pseudo-units. RT-Recognition Threshold as determined by ASTM E679 and EN13725. Result is dimensionless dilution ratio at which half the assessors recognize a character in the diluted odorous air. Odor Units(OU)or Odor Units per cubic meter(OU/m3)are commonly used pseudo-units. I-Perceived odor intensity as determined by ASTM E544. Intensity is expressed as average reported scale value on 10pt n-butanol in water static scale. HT-Hedonic Tone value. Average rating of assessors'opinion of odor pleasantness on scale of-10(most unpleasant)to+10(most pleasant). DR-the slope of the dose-response relationship of odor intensity with dilution(persistency of odor). Attachments St.Croix Sensory,Inc. CHAIN OF CUSTODY RECORD FOR ODOR SAMPLES lient _ C 1a12�5 Filvi ro..m.�n7-a/ Sampled By: '84 k-1-Mull odor Evamarim.:R q esmd:aq Page_of_ Project Name: ,e4, , t,)RRF 5A) Samplin--Date: O- g_O e _ For Laboratory use Only Comments: o Odor Evaluation a Report No. - 92 ep _- a � O� lane C Laboratory Sample No. No. Field No_ Sample Description Sample Piela H,S o Time (pp-) � � LN FN old ?,'IS-A- .22 9 X . Gl x..E PS /0,00 A /.3 X s 3 �F- 4 s 6 l:s0 r q.q �C 7 /V+a �tr n Qrs Jrs 2:/0P SCl Nr 9 10 II 12 'Wanstniffal Relinquished By Date lime Accepted By Data Time Comments R Exceptions Noted to Number of Stopping Boxes Received at St Crony Sensory Laboratory O'. "Odor Concentration:ASTM E679-04&EN13725 2003 and Odor beaeoty:— E544-10 St.Croix Sensory,Inc..1150 Stillwater Blvd.N..Stillwater,MN 55092 USA.Te.800-879-9353 ax:651-439-1065 a gmail:repons@fivesenses.com a Web:ww�vfivesenses.com Z AB G'OPZBS WHZTE' Bs:•Y_;,LLOW cr-1—'NZ' COPY P11VK (Izq � C-16-1 I06-1 I-'If I-G St. Croix Sensory, Inc. Odor Evaluation Report Report Number: 2021901 Project Name: Meridian WRRF Study Samples Collected: 8/5/20 Samples Received: 8/6/20 Samples Evaluated: 8/6/20 Report Prepared For: Webster Environmental Associates,Inc. 13121 Eastpoint Park Blvd, Ste. E Louisville, KY 40223 Report Prepared By: St.Croix Sensory,Inc. 1150 Stillwater Boulevard North Stillwater, MN 55082 U.S.A 1-800-879-9231 stcroix@fivesenses.com Data jrw�"At�- Release Authorization: Reviewed and Approved: Michelle Harty Charles M. McGinley, P.E. Laboratory Manager Technical Director St.Croix Sensory is ISO/IEC 1702S:2005 Accredited Perry Johnson Laboratory Accreditation,Inc. Accreditation No.:81047 Certificate No.:L18-374 Initial Accreditation Date:19 May 2014 Odor Evaluation Report C1�1-III St. Croix Sensory,Inc. Client: Webster Environmental Associates,Inc. Report Number: 2021901 Project Name: Meridian WRRF Study Samples Evaluated: 8/6/20 # Field No. Sample Description RT I HT DR Comments I 1 9 Aeration Basin 180 100 --- -1.9 --- 2 10 Daft#2 150 75 --- --- --- 3 11 Old Secondary Clarifier 180 110 --- --- --- 4 12 New Secondary Clarifier 170 75 --- --- --- 5 13 Headworks Biofilter 100 55 --- --- --- Outlet 6 14 RAS/WAS Tank 4,600 2,700 --- --- --- Odor Detection Threshold Testing(Evaluations)conducted in compliance with and under all conditions specified or required by ASTM E679 and EN13725 unless noted in report"Comments"column. The Client Chain of Custody(COC)attached to the Odor Evaluation Report provides information that may include sampling location(s),methods,and/or environmental conditions during sampling. Client,designated agents,and/or reviewers provide interpretation of results based on sampling conditions. DT-Detection Threshold as determined by ASTM E679 and EN13725. The Practical Detection Limit(PDL)of DT is 12,based on the nominal lowest dilution presentation ratio of 8.Result is dimensionless dilution ratio at which half the assessors detect the diluted air as different from the blank air. Odor Units (OU)or Odor Units per cubic meters(OU/m3)are commonly used as pseudo-units. RT-Recognition Threshold as determined by ASTM E679 and EN13725. Result is dimensionless dilution ratio at which half the assessors recognize a character in the diluted odorous air. Odor Units(OU)or Odor Units per cubic meter(OU/m3)are commonly used pseudo-units. I-Perceived odor intensity as determined by ASTM E544. Intensity is expressed as average reported scale value on 10pt n-butanol in water static scale. HT-Hedonic Tone value. Average rating of assessors'opinion of odor pleasantness on scale of-10(most unpleasant)to+10(most pleasant). DR-the slope of the dose-response relationship of odor intensity with dilution(persistency of odor). Report Number: 2021901 I I I Client: Webster Environmental Associates,Inc. CA, Project Name: Meridian WRRF Study St. Croix Sensory,Inc. Samples Evaluated: 8/6/2020 DT: 180 Comments: Field No: 9 RT: 100 Description: Aeration Basin I: -- - HT: -1.9 DR: --- Odor Descriptors Strength Descriptor r Sensation i No Odor = Decay -�0.0 1.8 Decay Taste - - Sulfur 4.1 Sulfur Confectionary Fish Fish Dairy _.6'U Sea Sea 1.5 Animal 0 Spice Animal 0.3 PIXW b d WPetroleumi � N Herbal Medicinal 1.1 Chemical Burnt ••• Grain , `N Plastics u d a Earth 2.0 Sulfidic vegetable Fruit Petroleum Non-sulficlic vegetable Vegetation Floral Chemical Floral Fruit Vegetation Burnt Grain Nan-sulfidicvegetable _ _ WoadHerbal Sulfidicvegetahle Earth Spice Dairy Confectionary Taste ua 20% 4A 6M MN M% Dose-Response Dose-Response as Power Law to.o to.o o u o 08 m o m o rt c rt c c 9 c n a c a c c " 4.0 " 4.0 z.o .� a z.o DT-Detection Threshold as determined by ASTM E679 and EN13725• ` o RT-Recognition Threshold as determined by ASTM E679 and EN13725• 0.0 0.0 0 1-Perceived odor intensity as determined by ASTM E544• 0.0 1.0 2.0 3.0 0.0 1.0 2.0 3.0 HT—Hedonic Tone value(pleasantness rating). Dose Dose DR—The slope of the dose-response(dilution—intensity)relationship. Log(Dilution Ratio Log Odor Concentration) P P y P' C—Dilution ratio of the odor sample presentation. Log I=n Log C+Logk Log I=n'Log(RT/Q+Log k' n,k,n',and k'—computed constants forthe specific odor sample. Page 2 of 8 Report Number: 2021901 I I I Client: Webster Environmental Associates,Inc. CA, Project Name: Meridian WRRF Study St. Croix Sensory,Inc. Samples Evaluated: 8/6/2020 DT: 150 Comments: Field No: 10 RT: 75 Description: Daft#2 I: --- HT: --- DR: --- Odor Descriptors Strength Descriptor r Sensation No Odor _I�•0 Decay Decay Taste - Sulfur Sulfur ry=- Confectionary Fish Fish Dairy _.6'U • Sea Sea Animal .0 Spice Animal � I d WPetroleum � N A 9, Herbal ' 0 Medicinal Chemical Burnt ••• Grain , `N Plastics Earth Sulfidic vegetable u d Fruit Petroleum Non-sulficlic vegetable Vegetation Floral = Chemical Floral Fruit Vegetation Burnt Grain Nan-sulfidicvegetable WoadHerbal Sulfidievegetahle Earth Spice Dairy Confectionary Taste 9% 20% 4A 6M MN M% Dose-Response Dose-Response as Power Law to.o to.o o o n m o m o rt c rt c c-9 c n a c a c c " 4.0 " 4.0 z.o .� a z.o DT-Detection Threshold as determined by ASTM E679 and EN13725• ` o RT-Recognition Threshold as determined by ASTM E679 and EN13725• 0.0 0.0 0 1-Perceived odor intensity as determined by ASTM E544• 0.0 1.0 2.0 3.0 0.0 1.0 2.0 3.0 HT—Hedonic Tone value(pleasantness rating). Dose Dose DR—The slope ofthe dose-response(dilution—intensity)relationship. Log(Dilution Ratio Log Odor Concentration) P P y P' C—Dilution ratio of the odor sample presentation. Log I=n Log C+Logk Log I=n'Log(RT/Q+Log k' n,k,n',and k'—computed constants forthe specific odor sample. Page 3 of 8 Report Number: 2021901 I I I Client: Webster Environmental Associates,Inc. CA, Project Name: Meridian WRRF Study St. Croix Sensory,Inc. Samples Evaluated: 8/6/2020 DT: 180 Comments: Field No: 11 RT: 110 Description: Old Secondary I: -- - Clarifier HT: --- DR: --- Odor Descriptors Strength Descriptor r Sensation No Odor _I�•0 Decay Decay Taste - Sulfur Sulfur ry=- Confectionary Fish Fish Dairy _.6'U • Sea Sea Animal .0 Spice Animal � I d WPetroleum � N A 9, Herbal ' 0 Medicinal Chemical Burnt ••• Grain , `N Plastics Earth Sulfidic vegetable u d Fruit Petroleum Non-sulficlic vegetable Vegetation Floral = Chemical Floral Fruit Vegetation Burnt Grain Nan-sulfidicvegetable WoadHerbal Sulfidievegetahle Earth Spice Dairy Confectionary Taste 9% 20% 4A 6M MN M% Dose-Response Dose-Response as Power Law to.o to.o o o n m o m o rt c rt c c-9 c n a c a c c " 4.0 " 4.0 z.o .� a z.o DT-Detection Threshold as determined by ASTM E679 and EN13725• ` o RT-Recognition Threshold as determined by ASTM E679 and EN13725• 0.0 0.0 0 1-Perceived odor intensity as determined by ASTM E544• 0.0 1.0 2.0 3.0 0.0 1.0 2.0 3.0 HT—Hedonic Tone value(pleasantness rating). Dose Dose DR—The slope ofthe dose-response(dilution—intensity)relationship. Log(Dilution Ratio Log Odor Concentration) P P y P' C—Dilution ratio of the odor sample presentation. Log I=n Log C+Logk Log I=n'Log(RT/Q+Log k' n,k,n',and k'—computed constants forthe specific odor sample. Page 4 of 8 Report Number: 2021901 I I I Client: Webster Environmental Associates,Inc. CA, Project Name: Meridian WRRF Study St. Croix Sensory,Inc. Samples Evaluated: 8/6/2020 DT: 170 Comments: Field No: 12 RT: 75 Description: New Secondary I: --- Clarifier HT: --- DR: --- Odor Descriptors Strength Descriptor r Sensation No Odor _I�•0 Decay Decay Taste - Sulfur Sulfur ry=- Confectionary Fish Fish Dairy _.6'U • Sea Sea Animal .0 Spice Animal � I d WPetroleum � N A 9, Herbal ' 0 Medicinal Chemical Burnt ••• Grain , `N Plastics Earth Sulfidic vegetable u d Fruit Petroleum Non-sulficlic vegetable Vegetation Floral = Chemical Floral Fruit Vegetation Burnt Grain Nan-sulfidicvegetable WoadHerbal Sulfidievegetahle Earth Spice Dairy Confectionary Taste 9% 20% 4A 6M MN M% Dose-Response Dose-Response as Power Law to.o to.o o o n m o m o rt c rt c c-9 c n a c a c c " 4.0 " 4.0 z.o .� a z.o DT-Detection Threshold as determined by ASTM E679 and EN13725• ` o RT-Recognition Threshold as determined by ASTM E679 and EN13725• 0.0 0.0 0 1-Perceived odor intensity as determined by ASTM E544• 0.0 1.0 2.0 3.0 0.0 1.0 2.0 3.0 HT—Hedonic Tone value(pleasantness rating). Dose Dose DR—The slope ofthe dose-response(dilution—intensity)relationship. Log(Dilution Ratio Log Odor Concentration) P P y P' C—Dilution ratio of the odor sample presentation. Log I=n Log C+Logk Log I=n'Log(RT/Q+Log k' n,k,n',and k'—computed constants forthe specific odor sample. Page 5 of 8 Report Number: 2021901 I I I Client: Webster Environmental Associates,Inc. CA, Project Name: Meridian WRRF Study St. Croix Sensory,Inc. Samples Evaluated: 8/6/2020 DT: 100 Comments: Field No: 13 RT: 55 Description: Headworks Biofilter I: --- Outlet HT: --- DR: --- Odor Descriptors Strength Descriptor r Sensation No Odor _I�•0 Decay Decay Taste - Sulfur Sulfur ry=- Confectionary Fish Fish Dairy _.6'U • Sea Sea Animal .0 Spice Animal � I d WPetroleum � N A 9, Herbal ' 0 Medicinal Chemical Burnt ••• Grain , `N Plastics Earth Sulfidic vegetable u d Fruit Petroleum Non-sulficlic vegetable Vegetation Floral = Chemical Floral Fruit Vegetation Burnt Grain Nan-sulfidicvegetable _ _ WoadHerbal Sulfidievegetahle Earth Spice Dairy Confectionary Taste 9% 20% 4A 6M MN M% Dose-Response Dose-Response as Power Law to.o to.o o o n m o m o rt c rt c c-9 c n a c a c c " 4.0 " 4.0 z.o .� a z.o DT-Detection Threshold as determined by ASTM E679 and EN13725• ` o RT-Recognition Threshold as determined by ASTM E679 and EN13725• 0.0 0.0 1-Perceived odor intensity as determined by ASTM E544• 0.0 1.0 2.0 3.0 0.0 1.0 2.0 3.0 HT—Hedonic Tone value(pleasantness rating). Dose Dose DR—The slope ofthe dose-response(dilution—intensity)relationship. Log(Dilution Ratio Log Odor Concentration) P P y P' C—Dilution ratio of the odor sample presentation. Log I=n Log C+Logk Log I=n'Log(RT/Q+Log k' n,k,n',and k'—computed constants forthe specific odor sample. Page 6 of 8 Report Number: 2021901 I I I Client: Webster Environmental Associates,Inc. CA, Project Name: Meridian WRRF Study St. Croix Sensory,Inc. Samples Evaluated: 8/6/2020 DT: 4,600 Comments: Field No: 14 RT: 2,700 Description: RAS/WAS Tank I: -- - HT: --- DR: --- Odor Descriptors Strength Descriptor r Sensation No Odor _I�•0 Decay Decay Taste - Sulfur Sulfur ry=- Confectionary Fish Fish Dairy _.6'U • Sea Sea Animal .0 Spice Animal � I d WPetroleum � N A 9, Herbal ' 0 Medicinal Chemical Burnt ••• Grain , `N Plastics Earth Sulfidic vegetable u d Fruit Petroleum Non-sulficlic vegetable Vegetation Floral = Chemical Floral Fruit Vegetation Burnt Grain Nan-sulfidicvegetable WoadHerbal Sulfidievegetahle Earth Spice Dairy Confectionary Taste 9% 20% 4A 6M MN M% Dose-Response Dose-Response as Power Law to.o to.o o o n m o m o rt c rt c — c-9 c n a c a c c " 4.0 " 4.0 z.o .� a z.o DT-Detection Threshold as determined by ASTM E679 and EN13725• ` o RT-Recognition Threshold as determined by ASTM E679 and EN13725• 0.0 0.0 1-Perceived odor intensity as determined by ASTM E544• 0.0 1.0 2.0 3.0 0.0 1.0 2.0 3.0 4.0 HT—Hedonic Tone value(pleasantness rating). Dose Dose DR—The slope ofthe dose-response(dilution—intensity)relationship. Log(Dilution Ratio Log Odor Concentration) P P y P' C—Dilution ratio of the odor sample presentation. Log I=n Log C+Logk Log I=n'Log(RT/Q+Log k' n,k,n',and k'—computed constants forthe specific odor sample. Page 7 of 8 Attachments St.Croix Sensory,Inc. CHAIN OF CUSTODY RECORD I r FOR ODOR SAMPLES_ _ Client: t It6�f to/v;ronm.ut't'et l/ Sampled By: L� /1! / Man Odor Evaluations Requested:(R) Page_of_ Project Name: Sampling Date: g 1-_;W - =o For laboratory use Only Comments: Odor Evaluation .b a I a❑ = = Report No. 9uIg01 Ua "� U F' •^ lane Field No. Sample Description Sample Field H,S O c C Laboratory Sample No. No. Time ( m) LN FN to DA7F--#2 °13Da -0►1 g ZOld Sec> —"�/'sue lowo"- .0 .5 l2 Al— Se-con. C�G r:F/•ml. . �D:t/!7/� .Qfc� X 5 i H"dt-�k o ,X4— 044 /1:10 A ,007 6 �� RF�S/WFts �nGc a.aQr 1 I X 7 9 10 11 12 •)•.]SangQliltal Reiinquishetl By Date Time accepted ey Date Time Comments ptions Noted Nmn of Shipping Boxes Receivetl at SL Croba Sensory Laboratory IR c L> 'Odor Concenttation:ASTM E679-04&EN337252003 and Odor Inteosiry:ASTM ES ]0 St.Cmix Sensory,Inc.a 1150 Stillwater Blvd.N-•Stillwater,MN 55052 U$Ae Te1:900-879-913I ax:651-459-1065 oEmail:reports@fivesrnses.com a web:wvnvSvesenses.com _+.•AB COPIES '1 "ZTE' & YEZ•Z•OW CLZE'N7- COPY PINK Appendix 6 ALS Environmental Reduced Sulfur Compound Testing Lab Results 2655 Park Center Dr., Suite A Simi Valley, CA 93065 T: +1 805 526 7161 www.aisgiobal.com AL5 A) LABORATORY REPORT August 12, 2020 Lee Blakeman Webster Environmental Associates 1 31 21 Eastpoint Park Blvd., Suite E Louisville, KY 40223 RE: Meridian WRRF Study/ 728 Dear Lee: Enclosed are the results of the samples submitted to our laboratory on August 5, 2020. For your reference, these analyses have been assigned our service request number P2004316. All analyses were performed according to our laboratory's NELAP and DoD-ELAP-approved quality assurance program. The test results meet requirements of the current NELAP and DoD-ELAP standards, where applicable, and except as noted in the laboratory case narrative provided. For a specific list of NELAP and DoD-ELAP-accredited analytes, refer to the certifications section at www.alsglobal.com. Results are intended to be considered in their entirety and apply only to the samples analyzed and reported herein. If you have any questions, please call me at (805) 526-7161 . Respectfully submitted, ALS I Environmental Kate Kaneko Project Manager RIGHT SOLUTIONS I RIGHT PARTNER 1 of 15 2655 Park Center Dr., Suite A Simi Valley, CA 93065 T: +1 805 526 7161 www.aisgiobal.com ALS A) Client: Webster Environmental Associates Service Request No: P2004316 Project: Meridian WRRF Study/ 728 CASE NARRATIVE The samples were received intact under chain of custody on August 5, 2020 and were stored in accordance with the analytical method requirements. Please refer to the sample acceptance check form for additional information. The results reported herein are applicable only to the condition of the samples at the time of sample receipt. Sulfur Analysis The samples were analyzed for twenty sulfur compounds per ASTM D 5504-12 using a gas chromatograph equipped with a sulfur chemiluminescence detector (SCD). All compounds with the exception of hydrogen sulfide and carbonyl sulfide are quantitated against the initial calibration curve for methyl mercaptan. This method is included on the laboratory's NELAP scope of accreditation, however it is not part of the DoD-ELAP accreditation. Samples 1 Old Headworks Influent" (P2004316-001) and "2 Influent PS" (P2004316-002) were received past the recommended holding time. The analysis was performed as soon as possible after receipt by the laboratory. The data is flagged to indicate the holding time exceedance. The results of analyses are given in the attached laboratory report. All results are intended to be considered in their entirety, and ALS Environmental(ALS)is not responsible for utilization of less than the complete report. Use of ALS Environmental (ALS)'s Name. Client shall not use ALS's name or trademark in any marketing or reporting materials, press releases or in any other manner ("Materials') whatsoever and shall not attribute to ALS any test result, tolerance or specification derived from ALS's data('Attribution')without ALS's prior written consent, which may be withheld by ALS for any reason in its sole discretion. To request ALS's consent, Client shall provide copies of the proposed Materials or Attribution and describe in writing Client's proposed use of such Materials or Attribution. If ALS has not provided written approval of the Materials or Attribution within ten (10) days of receipt from Client, Client's request to use ALS's name or trademark in any Materials or Attribution shall be deemed denied. ALS may, in its discretion, reasonably charge Client for its time in reviewing Materials or Attribution requests. Client acknowledges and agrees that the unauthorized use of ALS's name or trademark may cause ALS to incur irreparable harm for which the recovery of money damages will be inadequate. Accordingly, Client acknowledges and agrees that a violation shall justify preliminary injunctive relief. For questions contact the laboratory. RIGHT SOLUTIONS I RIGHT PARTNER 2of15 2655 Park Center Dr., Suite A Simi Valley, CA 93065 T: +1 805 526 7161 www.aisgiobal.com AL5 A) ALS Environmental - Simi Valley CERTIFICATIONS, ACCREDITATIONS, AND REGISTRATIONS Agency Web Site Number Alaska DEC http://dec.alaska.gov/eh/lab.aspx 17-019 Arizona DHS http://www.azdhs.gov/preparedness/state-laboratory/lab-licensure- AZ0694 certification/index.php#laboratory-licensure-home Florida DOH http://www.floridahealth.gov/licensing-and-regulation/environmental- E871020 (NELAP) laboratories/index.html Louisiana DEQ (NELAP) http://www.deq.louisiana.gov/page/la-lab-accreditation 05071 Maine DHHS http://www.maine.gov/dhhs/mecdc/environmental- 2018027 health/dwp/professionals/labCert.shtml Minnesota DOH (NELAP) http://www.health.state.mn.us/accreditation 1776326 New Jersey DEP (NELAP) http://www.nj_gov/dep/enforcement/oga.html CA009 New York DOH (NELAP) http://www.Wadsworth.org/labcert/elap/elap.html 11221 Oregon PHD http://www.oregon.gov/oha/ph/LaboratoryServices/EnvironmentalLaborat 4068-007 (NELAP) oryAccreditation/Pages/index.aspx Pennsylvania DEP http://www.dep pa.gov/Business/OtherPrograms/Labs/Pages/Laboratory- 68-03307 Accreditation-Program.aspx (Registration) PJLA 65818 (DoD ELAP) http://www.pjlabs.com/search accredited labs (Testing) Texas CEQ T10470441 3- (NELAP) http://www.tceq.texas.ctov/agency/qa/env_lab_accreditation.html 19-10 Utah DOH CA01627201 (NELAP) http://health.utah.gov/lab/lab_cert_env 9-10 Washington DOE http://www.ecy.wa.gov/programs/eap/labs/lab-accreditation.html C946 Analyses were performed according to our laboratory's NELAP and DoD-ELAP approved quality assurance program. A complete listing of specific NELAP and DoD-ELAP certified analytes can be found in the certifications section at www.alsglobal.com, or at the accreditation body's website. Each of the certifications listed above have an explicit Scope of Accreditation that applies to specific matrices/methods/analytes; therefore, please contact the laboratory for information corresponding to a articular certification. RIGHT SOLUTIONS I RIGHT PARTNER 3of15 ALS ENVIRONMENTAL DETAIL SUMMARY REPORT Client: Webster Environmental Associates Service Request: P2004316 Project ID: Meridian WRRF Study/728 en Date Received: 8/5/2020 Time Received: 10:05 00 0 kn kn Q Date Time H Client Sample ID Lab Code Matrix Collected Collected 1 Old Headworks Influent P20043 1 6-00 1 Air 8/4/2020 09:10 X 2 Influent PS P2004316-002 Air 8/4/2020 09:55 X 3 Headworks Biofilter Inlet P2004316-003 Air 8/4/2020 10:25 X 4 Centrifuge Exhaust P2004316-004 Air 8/4/2020 10:50 X 5 Centrate Tanks P2004316-005 Air 8/4/2020 11:30 X 6 Primary Clarifier P2004316-006 Air 8/4/2020 13:30 X 7 New Aeration Basins P2004316-007 Air 8/4/2020 14:15 X 8 Biosolids Pile P2004316-008 Air 8/4/2020 15:00 X 4of15 P2004316_Detail Sm ary 2008121221_LP.x1s-DETAIL SUMMARY C � U a d c m u maw � CY CL o CL CL Itr: N a U F to 'C o � ~ z CO m U m Y1 d a ¢ �Q © E Syunp w�? d z ii w �C in H I .o¢ a o m m 46[- a� a U— 3 o a CL 1 ffi 4 c L� N a a m m m c W E m m E �� t tZ ~ LD c Q g tr ui er ~ �NrR p Q. LL G 13 E ° V c f 7 N y � � O ik y E 1fE ivo m a @ a c g� f m z 7 u m a A O o O E L' ni ui to .V) F zm L � in Q c z CD a & n u � U Fr �, eo pe po ao Oe a, 3 N � � mm 0 D ] m a m o E �� N p3 LL Yf m er U m on g m r a a ar _ a 3 4 m w t N ���SSS p r m C \J .E v 5of15 ALS Environmental Sample Acceptance Check Form Client: Webster Environmental Associates Work order: P2004316 Project: Meridian WRRF Study/728 Sample(s)received on: 8/5/20 Date opened: 8/5/20 by: DENISE.POSADA Note: This form is used for all samples received by ALS. The use of this form for custody seals is strictly meant to indicate presence/absence and not as an indication of compliance or nonconformity. Thermal preservation and pH will only be evaluated either at the request of the client and/or as required by the method/SOP. Yes No N/A 1 Were sample containers properly marked with client sample ID? 0 ❑ ❑ 2 Did sample containers arrive in good condition? 0 ❑ ❑ 3 Were chain-of-custody papers used and filled out? 0 ❑ ❑ 4 Did sample container labels and/or tags agree with custody papers? 0 ❑ ❑ 5 Was sample volume received adequate for analysis? 0 ❑ ❑ 6 Are samples within specified holding times? 0 ❑ ❑ 7 Was proper temperature(thermal preservation)of cooler at receipt adhered to? ❑ ❑ 0 8 Were custody seals on outside of cooler/Box/Container? ❑ 0 ❑ Location of seal(s)? Sealing Lid? ❑ ❑ 0 Were signature and date included? ❑ ❑ 0 Were seals intact? ❑ ❑ 0 9 Do containers have appropriate preservation,according to method/SOP or Client specified information? ❑ ❑ 0 Is there a client indication that the submitted samples are pH preserved? ❑ ❑ 0 Were VOA vials checked for presence/absence of air bubbles? ❑ ❑ 0 Does the client/method/SOP require that the analyst check the sample pH and if necessary alter it? ❑ ❑ 0 10 Tubes: Are the tubes capped and intact? ❑ ❑ 0 11 Badges: Are the badges properly capped and intact? ❑ ❑ 0 Are dual bed badges separated and individually capped and intact? ❑ ❑ 0 Lab Sample ID Container Required Received Adjusted VOA Headspace Receipt/Preservation Description pH* pH pH (Presence/Absence) Comments P2004316-001.01 1.0 L Tedlar Bag P2004316-002.01 1.0 L Tedlar Bag P2004316-003.01 1.0 L Tedlar Bag P2004316-004.01 1.0 L Tedlar Bag P2004316-005.01 1.0 L Tedlar Bag P2004316-006.01 1.0 L Tedlar Bag P2004316-007.01 1.0 L Tedlar Bag P2004316-008.01 1.0 L Tedlar Bag Explain any discrepancies:(include lab sample ID numbers): Samples -001 &-002 received out of hold time RSK-MEEPP,HCL(pH<2);RSK-CO2,(pH 5-8);Sulfur(pH>4) 6of15 P2004316_Webster Environmental Associates_Meridian WRRF Study_728.xls-Page 1 of 1 8/12/20 1:07 PM AILS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: 1 Old Headworks Influent ALS Project ID: P2004316 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004316-001 Test Code: ASTM D 5504-12 Date Collected: 8/4/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 09:10 Analyst: Gilbert Gutierrez Date Received: 8/5/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/5/20 Test Notes: H3 Time Analyzed: 12:44 Volume(s)Analyzed: 1.0 MI(S) CAS# Compound Result MRL Result MRL Data µg/m' µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 210 7.0 150 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan 28 9.8 14 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide 39 13 15 5.0 75-15-0 Carbon Disulfide 8.9 7.8 2.9 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide 20 9.6 5.1 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. H3=Sample was received and analyzed past holding time. 7of15 P2004316_ASTM5504_2008121118_SC.xls-Sample 20SULFURALS - Page No.: AILS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: 2 Influent PS ALS Project ID: P2004316 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004316-002 Test Code: ASTM D 5504-12 Date Collected: 8/4/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 09:55 Analyst: Gilbert Gutierrez Date Received: 8/5/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/5/20 Test Notes: H3 Time Analyzed: 13:02 Volume(s)Analyzed: 1.0 MI(S) CAS# Compound Result MRL Result MRL Data µg/m' µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 1,500 7.0 1,100 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan 210 9.8 110 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide 58 13 23 5.0 75-15-0 Carbon Disulfide 9.3 7.8 3.0 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide 28 9.6 7.3 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. H3=Sample was received and analyzed past holding time. 8of15 P2004316_ASTM5504_2008121118_SC.xls-Sample(2) 20SULFURALS - Page No.: AILS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: 3 Headworks Biofilter Inlet ALS Project ID: P2004316 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004316-003 Test Code: ASTM D 5504-12 Date Collected: 8/4/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 10:25 Analyst: Gilbert Gutierrez Date Received: 8/5/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/5/20 Test Notes: Time Analyzed: 10:25 Volume(s)Analyzed: 1.0 MI(S) CAS# Compound Result MRL Result MRL Data µg/m3 µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 83 7.0 60 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan ND 9.8 ND 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide ND 13 ND 5.0 75-15-0 Carbon Disulfide ND 7.8 ND 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide ND 9.6 ND 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. 9of15 P2004316_ASTM5504_2008121118_SC.xls-Sample(3) 20SULFURALS - Page No.: AILS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: 4 Centrifuge Exhaust ALS Project ID: P2004316 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004316-004 Test Code: ASTM D 5504-12 Date Collected: 8/4/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 10:50 Analyst: Gilbert Gutierrez Date Received: 8/5/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/5/20 Test Notes: Time Analyzed: 10:50 Volume(s)Analyzed: 0.20 ml(s) CAS# Compound Result MRL Result MRL Data µg/m' µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 120,000 35 89,000 25 463-58-1 Carbonyl Sulfide ND 61 ND 25 74-93-1 Methyl Mercaptan 75 49 38 25 75-08-1 Ethyl Mercaptan ND 64 ND 25 75-18-3 Dimethyl Sulfide ND 64 ND 25 75-15-0 Carbon Disulfide 130 39 42 13 75-33-2 Isopropyl Mercaptan ND 78 ND 25 75-66-1 tert-Butyl Mercaptan ND 92 ND 25 107-03-9 n-Propyl Mercaptan 84 78 27 25 624-89-5 Ethyl Methyl Sulfide ND 78 ND 25 110-02-1 Thiophene ND 86 ND 25 513-44-0 Isobutyl Mercaptan ND 92 ND 25 352-93-2 Diethyl Sulfide ND 92 ND 25 109-79-5 n-Butyl Mercaptan ND 92 ND 25 624-92-0 Dimethyl Disulfide ND 48 ND 13 616-44-4 3-Methylthiophene ND 100 ND 25 110-01-0 Tetrahydrothiophene ND 90 ND 25 638-02-8 2,5-Dimethylthiophene ND 110 ND 25 872-55-9 2-Ethylthiophene ND 110 ND 25 110-81-6 Diethyl Disulfide ND 62 ND 13 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. 10 of 15 P2004316_ASTM5504_2008121118_SC.xls-Sample(4) 20SULFURALS - Page No.: AILS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: 5 Centrate Tanks ALS Project ID: P2004316 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004316-005 Test Code: ASTM D 5504-12 Date Collected: 8/4/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 11:30 Analyst: Gilbert Gutierrez Date Received: 8/5/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/5/20 Test Notes: Time Analyzed: 11:08 Volume(s)Analyzed: 1.0 MI(S) CAS# Compound Result MRL Result MRL Data µg/m' µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 79 7.0 57 5.0 463-58-1 Carbonyl Sulfide 13 12 5.3 5.0 74-93-1 Methyl Mercaptan 18 9.8 9.1 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide ND 13 ND 5.0 75-15-0 Carbon Disulfide 26 7.8 8.3 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide 18 9.6 4.7 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. 11 of 15 P2004316_ASTM5504_2008121118_SC.xls-Sample(5) 20SULFURALS - Page No.: AILS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: 6 Primary Clarifier ALS Project ID: P2004316 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004316-006 Test Code: ASTM D 5504-12 Date Collected: 8/4/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 13:30 Analyst: Gilbert Gutierrez Date Received: 8/5/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/5/20 Test Notes: Time Analyzed: 11:51 Volume(s)Analyzed: 1.0 MI(S) CAS# Compound Result MRL Result MRL Data µg/m' µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 5,500 7.0 4,000 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan 310 9.8 160 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide 55 13 22 5.0 75-15-0 Carbon Disulfide 33 7.8 10 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide 32 9.6 8.3 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. 12 of 15 P2004316_ASTM5504_2008121118_SC.xls-Sample(6) 20SULFURALS - Page No.: AILS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: 7 New Aeration Basins ALS Project ID: P2004316 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004316-007 Test Code: ASTM D 5504-12 Date Collected: 8/4/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 14:15 Analyst: Gilbert Gutierrez Date Received: 8/5/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/5/20 Test Notes: Time Analyzed: 12:07 Volume(s)Analyzed: 1.0 MI(s) CAS# Compound Result MRL Result MRL Data µg/m' µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 22,000 7.0 16,000 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan 1,300 9.8 650 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide 110 13 45 5.0 75-15-0 Carbon Disulfide 34 7.8 11 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide 100 9.6 26 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. 13 of 15 P2004316_ASTM5504_2008121118_SC.xls-Sample(7) 20SULFURALS - Page No.: AILS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: 8 Biosolids Pile ALS Project ID: P2004316 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004316-008 Test Code: ASTM D 5504-12 Date Collected: 8/4/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 15:00 Analyst: Gilbert Gutierrez Date Received: 8/5/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/5/20 Test Notes: Time Analyzed: 12:23 Volume(s)Analyzed: 1.0 MI(S) CAS# Compound Result MRL Result MRL Data µg/m' µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 35 7.0 25 5.0 463-58-1 Carbonyl Sulfide 13 12 5.3 5.0 74-93-1 Methyl Mercaptan 110 9.8 57 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide 190 13 73 5.0 75-15-0 Carbon Disulfide 34 7.8 11 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide 3,500 9.6 900 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. 14of15 P2004316_ASTM5504_2008121118_SC.xls-Sample(8) 20SULFURALS - Page No.: AILS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: Method Blank ALS Project ID: P2004316 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P200805-MB Test Code: ASTM D 5504-12 Date Collected: NA Instrument ID: Agilent 7890A/GC22/SCD Time Collected: NA Analyst: Gilbert Gutierrez Date Received: NA Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/05/20 Test Notes: Time Analyzed: 07:07 Volume(s)Analyzed: 1.0 MI(S) CAS# Compound Result MRL Result MRL Data µg/m' µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide ND 7.0 ND 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan ND 9.8 ND 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide ND 13 ND 5.0 75-15-0 Carbon Disulfide ND 7.8 ND 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide ND 9.6 ND 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. 15of15 P2004316_ASTM5504_2008121118_SC.x1s-MBlank 20SULFURALS - Page No.: 2655 Park Center Dr., Suite A Simi Valley, CA 93065 T: +1 805 526 7161 www.aisgiobal.com ALS LABORATORY REPORT August 20, 2020 Jim Ross Webster Environmental Associates 13121 Eastpoint Park Blvd., Suite E Louisville, KY 40223 RE: Meridian WRRF Study/ 728 Dear Jim: Enclosed are the results of the samples submitted to our laboratory on August 6, 2020. For your reference, these analyses have been assigned our service request number P2004339. All analyses were performed according to our laboratory's NELAP and DoD-ELAP-approved quality assurance program. The test results meet requirements of the current NELAP and DoD-ELAP standards, where applicable, and except as noted in the laboratory case narrative provided. For a specific list of NELAP and DoD-ELAP-accredited analytes, refer to the certifications section at www.alsglobal.com. Results are intended to be considered in their entirety and apply only to the samples analyzed and reported herein. If you have any questions, please call me at (805) 526-7161 . Respectfully submitted, ALS I Environmental Kate Kaneko Project Manager RIGHT SOLUTIONS I RIGHT PARTNER 1 of 11 2655 Park Center Dr., Suite A Simi Valley, CA 93065 T: +1 805 526 7161 www.aisgiobal.com ALS Client: Webster Environmental Associates Service Request No: P2004339 Project: Meridian WRRF Study/ 728 CASE NARRATIVE The samples were received intact under chain of custody on August 6, 2020 and were stored in accordance with the analytical method requirements. Please refer to the sample acceptance check form for additional information. The results reported herein are applicable only to the condition of the samples at the time of sample receipt. Sulfur Analysis The samples were analyzed for twenty sulfur compounds per ASTM D 5504-12 using a gas chromatograph equipped with a sulfur chemiluminescence detector (SCD). All compounds with the exception of hydrogen sulfide and carbonyl sulfide are quantitated against the initial calibration curve for methyl mercaptan. This method is included on the laboratory's NELAP scope of accreditation, however it is not part of the DoD-ELAP accreditation. Analyzed P2004339-002 out of hold time due to time received. The results of analyses are given in the attached laboratory report. All results are intended to be considered in their entirety, and ALS Environmental(ALS)is not responsible for utilization of less than the complete report. Use of ALS Environmental (ALS)'s Name. Client shall not use ALS's name or trademark in any marketing or reporting materials, press releases or in any other manner ("Materials') whatsoever and shall not attribute to ALS any test result, tolerance or specification derived from ALS's data('Attribution')without ALS's prior written consent, which may be withheld by ALS for any reason in its sole discretion. To request ALS's consent, Client shall provide copies of the proposed Materials or Attribution and describe in writing Client's proposed use of such Materials or Attribution. If ALS has not provided written approval of the Materials or Attribution within ten (10) days of receipt from Client, Client's request to use ALS's name or trademark in any Materials or Attribution shall be deemed denied. ALS may, in its discretion, reasonably charge Client for its time in reviewing Materials or Attribution requests. Client acknowledges and agrees that the unauthorized use of ALS's name or trademark may cause ALS to incur irreparable harm for which the recovery of money damages will be inadequate. Accordingly, Client acknowledges and agrees that a violation shall justify preliminary injunctive relief. For questions contact the laboratory. RIGHT SOLUTIONS I RIGHT PARTNER 2of11 2655 Park Center Dr., Suite A Simi Valley, CA 93065 T: +1 805 526 7161 www.aisgiobal.com ALS ALS Environmental - Simi Valley CERTIFICATIONS, ACCREDITATIONS, AND REGISTRATIONS Agency Web Site Number Alaska DEC http://dec.alaska.gov/eh/lab.aspx 17-019 Arizona DHS http://www.azdhs.gov/preparedness/state-laboratory/lab-licensure- AZ0694 certification/index.php#laboratory-licensure-home Florida DOH http://www.floridahealth.gov/licensing-and-regulation/environmental- E871020 (NELAP) laboratories/index.html Louisiana DEQ (NELAP) http://www.deq.louisiana.gov/page/la-lab-accreditation 05071 Maine DHHS http://www.maine.gov/dhhs/mecdc/environmental- 2018027 health/dwp/professionals/labCert.shtml Minnesota DOH (NELAP) http://www.health.state.mn.us/accreditation 1776326 New Jersey DEP (NELAP) http://www.nj_gov/dep/enforcement/oga.html CA009 New York DOH (NELAP) http://www.Wadsworth.org/labcert/elap/elap.html 11221 Oregon PHD http://www.oregon.gov/oha/ph/LaboratoryServices/EnvironmentalLaborat 4068-007 (NELAP) oryAccreditation/Pages/index.aspx Pennsylvania DEP http://www.dep pa.gov/Business/OtherPrograms/Labs/Pages/Laboratory- 68-03307 Accreditation-Program.aspx (Registration) PJLA 65818 (DoD ELAP) http://www.pjlabs.com/search accredited labs (Testing) Texas CEQ T10470441 3- (NELAP) http://www.tceq.texas.ctov/agency/qa/env_lab_accreditation.html 19-10 Utah DOH CA01627201 (NELAP) http://health.utah.gov/lab/lab_cert_env 9-10 Washington DOE http://www.ecy.wa.gov/programs/eap/labs/lab-accreditation.html C946 Analyses were performed according to our laboratory's NELAP and DoD-ELAP approved quality assurance program. A complete listing of specific NELAP and DoD-ELAP certified analytes can be found in the certifications section at www.alsglobal.com, or at the accreditation body's website. Each of the certifications listed above have an explicit Scope of Accreditation that applies to specific matrices/methods/analytes; therefore, please contact the laboratory for information corresponding to a articular certification. RIGHT SOLUTIONS I RIGHT PARTNER 3of11 ALS ENVIRONMENTAL DETAIL SUMMARY REPORT Client: Webster Environmental Associates Service Request: P2004339 Project ID: Meridian WRRF Study/728 o� Date Received: 8/6/2020 Time Received: 10:00 00 0 0 A Date Time Client Sample ID Lab Code Matrix Collected Collected DAFT#2 P2004339-001 Air 8/5/2020 09:35 x Old Secondary Clarifier P2004339-002 Air 8/5/2020 10:10 x New Secondary Clarifier P2004339-003 Air 8/5/2020 10:45 x RAS/WAS Tank P2004339-004 Air 8/5/2020 14:30 x P2004339_Detail Summary 2008201100_NN.xls-DETAIL SUMMARY 4of11 C e � O m d V m t a cT E ¢ 70 � p a u K Q m La `m a n p o O Z m a 07 m IM a a �a 1 w mz a s�UnA(��'� m J Y Tp m a as U a 2 2 �n—a° 4ti M1 M M r z c o aul v 0 i in as � � w a� � o M v e 4D Q } r m m Q a e o 1 ,� 3 a �LL o . " d s o EL LL lu W H W K m a _fs M ^c E' Y. m mi' a uma p a' O E a K r a a a E ; rE- E c Q m ® [Y [Y R a U � � maA 0 �,^ � _ B c is N to Oe �p a o m v U c �c o a; t' m a Wm a E = F d m _ °0 E .°n. Z r cmitna U. Qr JQ FAra a ° m co E 3 r°nao c m = u m 9 R � ✓1 m a°9i m m N 4 N K 3 9 Ea' cr 0 c 5of11 ALS Environmental Sample Acceptance Check Form Client: Webster Environmental Associates Work order: P2004339 Project: Meridian WRRF Study/728 Sample(s)received on: 8/6/20 Date opened: 8/6/20 by: DENISE.POSADA Note: This form is used for all samples received by ALS. The use of this form for custody seals is strictly meant to indicate presence/absence and not as an indication of compliance or nonconformity. Thermal preservation and pH will only be evaluated either at the request of the client and/or as required by the method/SOP. Yes No N/A 1 Were sample containers properly marked with client sample ID? ❑X ❑ ❑ 2 Did sample containers arrive in good condition? 0 ❑ ❑ 3 Were chain-of-custody papers used and filled out? 0 ❑ ❑ 4 Did sample container labels and/or tags agree with custody papers? 0 ❑ ❑ 5 Was sample volume received adequate for analysis? 0 ❑ ❑ 6 Are samples within specified holding times? 0 ❑ ❑ 7 Was proper temperature(thermal preservation)of cooler at receipt adhered to? ❑ ❑ IE 8 Were custody seals on outside of cooler/Box/Container? ❑ ❑x ❑ Location of seal(s)? Sealing Lid? ❑ ❑ IE Were signature and date included? ❑ ❑ ❑x Were seals intact? ❑ ❑ ❑x 9 Do containers have appropriate preservation,according to method/SOP or Client specified information? ❑ ❑ ❑x Is there a client indication that the submitted samples are pH preserved? ❑ ❑ ❑x Were VOA vials checked for presence/absence of air bubbles? ❑ ❑ ❑x Does the client/method/SOP require that the analyst check the sample pH and if necessary alter it? ❑ ❑ ❑X 10 Tubes: Are the tubes capped and intact? ❑ ❑ 0 11 Badges: Are the badges properly capped and intact? ❑ ❑ 0 Are dual bed badges separated and individually capped and intact? ❑ ❑ 0 Lab Sample ID Container Required Received Adjusted VOA Headspace Receipt/Preservation Description pH* pH pH (Presence/Absence) Comments P2004339-001.01 1.0 L Tedlar Bag P2004339-002.01 1.0 L Tedlar Bag P2004339-003.01 1.0 L Tedlar Bag P2004339-004.01 1.0 L Tedlar Bag Explain any discrepancies:(include lab sample ID numbers): Sample-001 was received out of HT RSK-MEEPP,HCL(pH<2);RSK-CO2,(pH 5-8);Sulfur(pH>4) P2004339 Webster Environmental Associates_Meridian WRRF Study_728.xls-Page 1 of 1 6of11 8/20/20 1:26 PM - ALS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: DAFT#2 ALS Project ID: P2004339 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004339-001 Test Code: ASTM D 5504-12 Date Collected: 8/5/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 09:35 Analyst: Gilbert Gutierrez Date Received: 8/6/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/6/20 Test Notes: H3 Time Analyzed: 11:04 Volume(s)Analyzed: 1.0 MI(s) CAS# Compound Result MRL Result MRL Data µg/W µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide ND 7.0 ND 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan ND 9.8 ND 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide ND 13 ND 5.0 75-15-0 Carbon Disulfide ND 7.8 ND 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide ND 9.6 ND 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. H3 =Sample was received and analyzed past holding time. P2004339_ASTM5504_2008200832SCAs-Sample 7of11 20SULFUR.XLS - Page No.: ALS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: Old Secondary Clarifier ALS Project ID: P2004339 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004339-002 Test Code: ASTM D 5504-12 Date Collected: 8/5/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 10:10 Analyst: Gilbert Gutierrez Date Received: 8/6/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/6/20 Test Notes: H1 Time Analyzed: 10:20 Volume(s)Analyzed: 1.0 MI(s) CAS# Compound Result MRL Result MRL Data µg/W µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 12 7.0 8.8 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan ND 9.8 ND 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide ND 13 ND 5.0 75-15-0 Carbon Disulfide ND 7.8 ND 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide ND 9.6 ND 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. H1 =Sample analysis performed past holding time. See case narrative. P2004339_ASTM5504_2008200832SCAs-Sample(2) 8of11 20SULFUR.XLS - Page No.: ALS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: New Secondary Clarifier ALS Project ID: P2004339 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004339-003 Test Code: ASTM D 5504-12 Date Collected: 8/5/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 10:45 Analyst: Gilbert Gutierrez Date Received: 8/6/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/6/20 Test Notes: Time Analyzed: 10:35 Volume(s)Analyzed: 1.0 MI(s) CAS# Compound Result MRL Result MRL Data µg/m' µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 9.7 7.0 6.9 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan ND 9.8 ND 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide ND 13 ND 5.0 75-15-0 Carbon Disulfide 8.5 7.8 2.7 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide ND 9.6 ND 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. P2004339_ASTM5504_2008200832SCAs-Sample(3) 9of11 20SULFUR.XLS - Page No.: ALS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: RAS/WAS Tank ALS Project ID: P2004339 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P2004339-004 Test Code: ASTM D 5504-12 Date Collected: 8/5/20 Instrument ID: Agilent 7890A/GC22/SCD Time Collected: 14:30 Analyst: Gilbert Gutierrez Date Received: 8/6/20 Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/6/20 Test Notes: Time Analyzed: 11:20 Volume(s)Analyzed: 1.0 MI(s) CAS# Compound Result MRL Result MRL Data µg/W µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide 710 7.0 510 5.0 463-58-1 Carbonyl Sulfide 24 12 9.9 5.0 74-93-1 Methyl Mercaptan 17 9.8 8.8 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide 100 13 41 5.0 75-15-0 Carbon Disulfide 72 7.8 23 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide 12 9.6 3.1 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. P2004339_ASTM5504_2008200832SCAs-Sample(4) 10of11 20SULFUR.XLS - Page No.: ALS ENVIRONMENTAL RESULTS OF ANALYSIS Page 1 of 1 Client: Webster Environmental Associates Client Sample ID: Method Blank ALS Project ID: P2004339 Client Project ID: Meridian WRRF Study/728 ALS Sample ID: P200806-MB Test Code: ASTM D 5504-12 Date Collected: NA Instrument ID: Agilent 7890A/GC22/SCD Time Collected: NA Analyst: Gilbert Gutierrez Date Received: NA Sample Type: 1.0 L Tedlar Bag Date Analyzed: 8/06/20 Test Notes: Time Analyzed: 08:10 Volume(s)Analyzed: 1.0 MI(s) CAS# Compound Result MRL Result MRL Data µg/W µg/m3 ppbV ppbV Qualifier 7783-06-4 Hydrogen Sulfide ND 7.0 ND 5.0 463-58-1 Carbonyl Sulfide ND 12 ND 5.0 74-93-1 Methyl Mercaptan ND 9.8 ND 5.0 75-08-1 Ethyl Mercaptan ND 13 ND 5.0 75-18-3 Dimethyl Sulfide ND 13 ND 5.0 75-15-0 Carbon Disulfide ND 7.8 ND 2.5 75-33-2 Isopropyl Mercaptan ND 16 ND 5.0 75-66-1 tert-Butyl Mercaptan ND 18 ND 5.0 107-03-9 n-Propyl Mercaptan ND 16 ND 5.0 624-89-5 Ethyl Methyl Sulfide ND 16 ND 5.0 110-02-1 Thiophene ND 17 ND 5.0 513-44-0 Isobutyl Mercaptan ND 18 ND 5.0 352-93-2 Diethyl Sulfide ND 18 ND 5.0 109-79-5 n-Butyl Mercaptan ND 18 ND 5.0 624-92-0 Dimethyl Disulfide ND 9.6 ND 2.5 616-44-4 3-Methylthiophene ND 20 ND 5.0 110-01-0 Tetrahydrothiophene ND 18 ND 5.0 638-02-8 2,5-Dimethylthiophene ND 23 ND 5.0 872-55-9 2-Ethylthiophene ND 23 ND 5.0 110-81-6 Diethyl Disulfide ND 12 ND 2.5 ND=Compound was analyzed for,but not detected above the laboratory reporting limit. MRL=Method Reporting Limit-The minimum quantity of a target analyte that can be confidently determined by the referenced method. P2004339_ASTM5504_2008200832_SC.xls-MB" 11 of 11 20SULFUR.XLS - Page No.: Appendix C Odalog Charts C:\Users\leebl\Desktop\MeridianOdalogs\190601562_OldHeadworks Influent_8-4-20.acrudata: (Old Headworks Diversion Box] V W 6 —H25 (PPM) —Temperature(°F) —}tumidity (%) ,r—Battery(Volts) [7/21/2020,1:57:27 PM-06:00--- 814/2020,9:45:27 AM-06:00][H25-190601562] Meridian W RRF Old Headworks Diversion Box 100 -120 2s s0 6 100 20 5 60 W v 15 - -ti s0 ( a `4 ^ 't rNy 40 3 0 _ _ o 10 o 6a ~rr 2 s z0 `40 1 0 22 Jul 24 Jul 26 Jul 28 Jul 30 Jul 01 Aug 03 Aug 0 0 n Average:3.38 PPM; Minimum: 0 PPM; Maximum: 28 PPM [7/21/2020,1:57:27 PM-06:00--- 8/4/2020,9:45:27 AM-06:001 C:\Users\leebl\Desktop\MeridianOdalags\190501537_InfluenlPS_8-4-20.acrudata: [Influent Pump Station] —H25 (PPM) —Temperature(OF) —}-tumidity (%) —Battery(Volts) [7/21/2020,2:00:53 PM-06:00--- 8/4/2020,9:51:53 AM-06:00]jH25-190501537] Meridian WRRF Influent Pump Station 1oa 120 -� 40 80 6 10D I` 5 3fl m 60 p3 _ 3 80 ro 4 rNv 2D 40 3 0 M 'n I i! V 10 60� 20 2 `40 1 D 0 D 22 Jul 24 Jul 26 Jul 28 Jul 30 Jul 01 Aug 03 Aug II II Average:15.04 PPM; Minimum: 0 PPM; Maximum:46 PPM [7/21/2020,2:00:53 PM-06:00--- 8/4/2020,9:51:53 AM-06:001 C:\Users\leebl\Desktop\Meridian Oda logs\180500557_CentrifugEExhaust_8-4-20.acrudata: [Centrifuge Exhaust] w f—1125 (PPM) —Temperature(°F) —Humidity (%) /—Battery(Volts) [7121/2020,2:29:13 PM-06:00--- 8/4/2020,10:50:13 AM-06:00][H25-180500557] Meridian W RRF Centrifuge Exhaust 100 -120 800 80 -G '100 -5 600. m 60 p� jjj 3 _ � rt a -SO m -4 ro a CL 2 � 400 r�o 40 -3 0 2 o rr 60 7r `~ v W -2 200 20 _1 -40 0 0 -0 22 Jul 24 Jul 26 Jul 28 Jul 30 Jul 01 Aug 03 Aug II II Average:0.00 PPM; Minimum: 0 PPM; Maximum: 0 PPM [7/21/2020,2:29:13 PM-06:00--- 8/4/2020,10:50:13 AM-06:001 C:\Users\leebl\Desktop\Meridian Oda logs\150200002_CentrateTank_B-4-20.acrudata: [Centrate Tank] w f—H25 (PPM) —Temperature(°F) —Humidity (%) ,r-Battery(Volts) [7/21/2020,2:36:34 PM-06:00--- 8/4/2020,11:36:34 AM-06:00][H25-150200002] Meridian W RRF Centrate Tank 100 -120 $0 15 6 100 D 60 5 c 0. 10 r8o (D -4 ro r%j `40 C ry = a -3 O -so 0 5 W 2 20 140 1 0 22 Jul 24 Jul 26 Jul 28 Jul 30 Jul 01 Aug 03 Aug 0 0 II II Average:0.63 PPM; Minimum: 0 PPM; Maximum: 14 PPM [7/21/2020,2:36:34 PM-06:00---8/4/2020,11:36:34AM-06:00] C:\Users\leebl\Desktop\Meridian Oda lags`,160600079-PrimaryClarifier_8-4-20.acrudata: [Primary Clarifier #5 Effluent Launder] v ,r—H25 (PPM) —Temperature(°F) —Humidity (%) /—Battery(Volts) [7/21/2020,2-.50:18 PM-06:00--- 8/4/2020,1:20:18 PM-06:00][H25-160600079] Meridian W RRF Primary Clarifier #S Effluent Launder 100 1 160 " 120 14❑ 80 6 120 100 -5 co 100 " 3 60 2 c a_ `SO (D -4 ro a 80— FF � 'Y Ln `40 C r.i -3 ❑ = 60- o a u -60 -7 40" W 2 20 20 40 1 I 0 ❑ ❑ 22 Jul 24 Jul 26 Jul 28 Jul 30 Jul 01 Aug 03 Aug Average:7.77 PPM; Minimum: 0 PPM; Maximum: 167 PPM [7121/2020,2:50:18 PM-06:00--- 8/4/2020,1:20:18 PM-06:00] C:\Users\leebl\Desktop\Meridian Oda logs\180500607_DAFT2_8-4-20.aurudata: [DAFT #2 Exhaust] v w f—H25 (PPM) —Temperature(°F) —Humidity (%) /—Battery(Volts) [7/21/2020,1:37:59 PM-06:00--- 8/4/2020,3:16:59 PM-06:00][H25-180500607] Meridian W RRF DAFT#2 Exhaust 100 i `120 8❑ 16 -100 -5 3 m 60 co 3 m 0. 80 [( -4 Q ,Y n i z `40 -3 0 _ a u -60 -0 2 i 20 -40 1 0 —. _ ❑ 0 22 Jul 24 Jul 26 Jul 28 Jul 30 Jul 01 Aug 03 Aug Average:0.43 PPM; Minimum: 0 PPM; Maximum: 3 PPM [7/21/2020,1:37:59 PM-06:00---8/4/2020,3:16:59 PM-06:00] C:\Users\leebl\Desktop\MeridianOdalogs\160900130_RASWASrank_8-4-20.acrudata: [RAS/WAS Tank] —H2S (PPM) —Temperature(OF) —Battery(Volts) [7/21/2020,2:43:03 PM-06:00--- 814/2020,3:2S:03 PM-06:00] [H25-160900130] Meridian WRRF RAS/WAS Tank Y 120 sao L 6 Y lOfl -5 600 ID co `80 4 ro � v � r+ Ln 400 ' C -3 ❑ = a N -60 -2 200 - -40 '1 0 -0 22 Jul 24 Jul 26 Jul 28 Jul 30 Jul 01 Aug 03 Aug II li Average:0.00 PPM; Minimum: 0 PPM; Maximum: 0 PPM [7/21/2020,2:43:03 PM-06:00---8/4/2020,3.28:03 PM-06:00)