Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
CC - Storm Drainage Calcs
Storm Drainage Calculations Sagarra Subdivision No.2 Private Storm Drain Facilities Meridian, Idaho <SS R/yGj�F 1 21F3 8-21-23 �ossTK o�R°�5o� August 2023 Sagarra Subdivision P2 (Private Facilities) Meridian, Idaho Dsesign Criteria: Storage Design Storm: 100-yr Conveyance Design Storm: 100-yr(conveyance system; pipes, etc.) Pre Development Discharge: None Water Quality Design Storm: 2-yr Storm Peak flow rates were calculated for each sub-basin using the rational method (equation 1- 1). Storm rainfall intensities were derived from the 2-year, 10-year, 25-year and 100-year intensity duration frequency curves for Zone A using calculated times of concentration. The time of concentration was calculated for each sub-basin based on the runoff coefficient "C" as defined in the rational method peak flow rate equation, and the individual sub-basin slope and length (see equation 1-2). Q= CiA (equation 1-1) where; Q= Peak Flow Rate (cfs) C= Runoff Coefficient (dimensionless) i = Rainfall Intensity (inches/hour) A = Drainage Area (acres) 1.8(1.1—C)� t� _ � (equation 1-2) where; t,= Time of Concentration (minutes) C= Runoff Coefficient (dimensionless) D = Distance from Remotest Contributing Point (feet) S= Slope Along D The rational method for peak flow calculation assumes: 1) the rainfall occurs uniformly over the drainage area; 2) the peak rate of runoff can be reflected by the rainfall intensity averaged over a time period equal to the time of concentration of the drainage area; and 3) the frequency of runoff is the same as the frequency of rainfall used in the equation. C-Value Lots & ROW 0.62 Existing Pasture 0.2 (FLAT PASTURE -TIGHT CLAY) I ' I � 1 I — �G aw 8 $ 8W I L38 I = 25 ems. I (0 — / 17 a. a J I I / G L o H�-n= H / / I n3goy U 0 n —5 a ar a / 22-5= 0. �/'/5° I II 1II I II / / � � �/ / % ♦ 5 4 \ I III 2,0-5 j --5 5 I�I \� CONTACT DIGLINE / L 48 HOURS � — — BEFORE DIGGING 0 I 2-5 `23 5p — = M M I 1-800-342-IM / , // \ / /♦ N 00 I I \ / \ / 4 5 I I 4� 4 I I I— 6-4 N LLI BASIN—4 LIP:2578.44 I I 10 U cn I J I ,�5 / 541700 SF M LIP:2578.44 I Il N I W 00 / r' ♦ (PRIVATE) DI-3A DI-3B I I Q Ln z 251974 SF 43,265 SF j � i i � 0 0 P25: 0.79 CFS I 1 /� / R / ♦ /'�/ QP25: 0.70 CFS Q I I \ v w _ _ — — - - - - - - - - - - - — — — — — — — — — — — — — - — — — — " " �, � ' ,5—�' < , / QP100: II , QP100: 1.10CFS , 1 I II Q � _ - - � Bw / ��\ I 4E -5 - I I III \ I III (D I \ — — — — — — r — — — — — — — f a / / ,' /\ / - I i I II Q w QU' _ I. jaw I 5 / / J li — \ — — I I — I— II— �aw / , cz j / ♦/ / � - - — II ..�iI_-_ __ I / I II1 CI � SEEPAGE BED #3 5 W Z 8W 8W 8IN iw 8W 8W 8W 8W 8W 0BASIN #3 24 o / _ — v a — I I I ' /. - \♦� BASIN-5 TOTAL AREA= 69'239 SF _ _ _ _ II 24-5 4 5 - I I I V ���0L �� 23� L49 L51 _ — _ i � - i 26 439 SF t' I- M � o tea^ — — — — - I J _L5o I I— , (PRIVATE) / ' /�t 4 5 sw �gw \ / ins ���— 9-5 10-5 8-21-23 — +I I / I I S �O � 5 � tt t- J / ss MH RIm 2 �zss, I - 4 5 !�1 I / /I \ 1 I =C22 /� / NW 8 Inv 2 22 BASIN-8 � q— I x Inv 256 22' - /; / A / IR 7 7 -_ —2780 SF - - — BASIN3 (AC : : � � 8W 8W 8W 8W lu •, 5; : . .BASIN-7(PRIVATE) — , , — © I 6 39020 SF BASIN-6 4 5 �� °� _ _8s _ — — 8S 8S N / (PRIVATE) // I I I - 241500 SF - - =o O w-1 5 1 (PRIVATE) 3 5— I II Q IL - - 7 / - I � I I L — _ — .DI-1 B _ I�, T I / I / I I I II I , I N I / 3 a ( 11,618 SF I t o I _ - - - - I I - - - - - I I i -- 3 5 w ICI go I QP25: 0.23 CFS DI-2B I I I I — = — - - - L - - _ L— _ 17,312SF [ I I I 00 \ QP100: 0.32 CFS — — 37-5 1 / I _< QP25: 0.37 CFSpz og 1,4 1 Is I 1 / I a z QP100: 0.51 CFS z � -- — 8w 8w 312FT 262FT I - - - - - - - - - -_ —3 � I — — / LIP 2577.96 8W 8W i�\ni - - - R1N - - - - - - - - - W I �/ I - 8w I 14 z wJ O / I LIP:2579.25 LIP:2578.89 W LIP:2579.94 // /� I I > 91 III i LIP:2577.96 LIP:2579.25 LIP:2578.89 .g 312FT O h - — — — — LIP:2579.94 / ■ ■ 2F) FT _ _ �_�-� / � � I I w 1 DI- A M DI-2A / /' \\ 20,461 F — — — — — - - - - - - -BASIN-1 (ACHID) — � — Li 21,642 SF�P25: 0.41 CP25: 0.46 CFS —100: 0.57 CAS I� Q BASIN 2 (ACHID) x� N QP100: 0.64 CFS _ ,3_3 �3 \ in-7cn _ co I 4- / 3 u / I SEEPAGE BED #1 r / SEEPAGE BED #2 — I Z oI.3 SS MH„R — — I BASIN #1 / BASIN #2 , — 1 NS In 62. L— _ _ AL AREA- 32079SF- ' _ - - - — �� P� 6P1 — S n 2 62 P ——TOT — /— — _— — — — — — — TOTAL AREA38,954 SF- — — — ___— — — — — — — — O G. 6P1 _ - - — — — — E.G. E.G. E.G. E.G. E.G. III �0�. — — - - ---E.Gu I — �- - - - - E.G.— E.G. / — ZLL .F \ E.G. E E.G. E.G. E.G. E.G. E.G. E.G. > w ZC --------------- --------- - - - - - - - - - - - 48 G148--- ---- — __ __ - - - - --- 148 ----- — 48 — -- C' -- — — � Ir ------ d01— — ----------- ---- T — _------_— -- -------- -- --- --- --- --- --- -- --- --- --- --- — - -- ---- -- --- — --- --- --- --- CrF�° --- — -- m Z00 I#8 + 8 C—F4— ——— —48 M� L L54 I \ -- --- --- — -- 1u w YNN m _ - - "� Z N \ z ° W W (L � O a N O�OQ Co JOB NUMBER: N �� 0� LIJ� IDB2355 m Q`�O V� z SHEET NUMBER: DRAINAGE BASINS P 5�� Q SCALE: 1" = 40' �O 00 J DC. I w Qw BASIN 4 Pretreatment: SAND AND GREASE TRAP & FILTER SAND Storage: SEEPAGE BED C-Value Basin Area 54700 sqft 0.9 Not Used 0 sqft 0 Not Used 0 sqft 0 Basin Area: 54,700 sqft Runoff Coefficient: 0.90 Basin Length: 100 feet Delta Z: 1 ft Average Basin Slope: 1.00 % Time of Concentration: 10.00 min Intensity(2-year): 0.69 in/hr Qp (2-year): 0.78 cfs Intensity(25-year): 1.85 in/hr Qp (25-year): 2.09 cfs Intensity(50-year): 2.20 in/hr Qp (50-year): 2.49 cfs Intensity 0i e . i0 Basin #5 Pretreatment: SAND AND GREASE TRAP & FILTER SAND Storage: SEEPAGE BED C-Value Basin Area 26439 sqft 0.9 Not Used 0 sqft 0 Not Used 0 sqft 0 Basin Area: 26,439 sqft Runoff Coefficient: 0.90 Basin Length: 100 feet Delta Z: 1 ft Average Basin Slope: 1.00 % Time of Concentration: 10.00 min Intensity(2-year): 0.69 in/hr Qp (2-year): 0.38 cfs Intensity(25-year): 1.85 in/hr Qp (25-year): 1.01 cfs Intensity(50-year): 2.20 in/hr Qp (50-year): 1.20 cfs Intensity 11 Q 11 Basin #6 Pretreatment: SAND AND GREASE TRAP & FILTER SAND Storage: SEEPAGE BED C-Value Basin Area 24500 sqft 0.9 Not Used 0 sqft 0 Not Used 0 sqft 0 Basin Area: 24,500 sqft Runoff Coefficient: 0.90 Basin Length: 100 feet Delta Z: 1 ft Average Basin Slope: 1.00 % Time of Concentration: 10.00 min Intensity(2-year): 0.69 in/hr Qp (2-year): 0.35 cfs Intensity(25-year): 1.85 in/hr Qp (25-year): 0.94 cfs Intensity(50-year): 2.20 in/hr Qp (50-year): 1.11 cfs Intensity 11 Q 11 Basin #7 Pretreatment: SAND AND GREASE TRAP & FILTER SAND Storage: SEEPAGE BED C-Value Basin Area 39020 sqft 0.9 Not Used 0 sqft 0 Not Used 0 sqft 0 Basin Area: 39,020 sqft Runoff Coefficient: 0.90 Basin Length: 100 feet Delta Z: 1 ft Average Basin Slope: 1.00 % Time of Concentration: 10.00 min Intensity(2-year): 0.69 in/hr Qp (2-year): 0.56 cfs Intensity(25-year): 1.85 in/hr Qp (25-year): 1.49 cfs Intensity(50-year): 2.20 in/hr Qp (50-year): 1.77 cfs Intensity 11 Q 11 1 ' cfs Basin #8 Pretreatment: SAND AND GREASE TRAP & FILTER SAND Storage: SEEPAGE BED C-Value Basin Area 2780 sqft 0.9 Not Used 0 sqft 0 Not Used 0 sqft 0 Basin Area: 2,780 sqft Runoff Coefficient: 0.90 Basin Length: 100 feet Delta Z: 1 ft Average Basin Slope: 1.00 % Time of Concentration: 10.00 min Intensity(2-year): 0.69 in/hr Qp (2-year): 0.04 cfs Intensity(25-year): 1.85 in/hr Qp (25-year): 0.11 cfs Intensity(50-year): 2.20 in/hr Qp (50-year): 0.13 cfs Intensity 11 Q 11 1 Calculation Summary INLET Q100 TC min. BASIN 4 2.92 10.00 BASIN 5 1.41 10.00 BASIN 6 1.31 10.00 BASIN 7 2.08 10.00 BASIN 8 0.15 10.00 Sand And Grease Trap Throat Velocity The target throat velocity design value is 0.5 ft/sec through the baffles of the S&G trap. 1000 GAL AREA= 8.61 SF DB 350 Throat Area = 1.42 SF Baffle/Box Width = 62 inches Baffle/Box Width = 41 inches Throat Width = 20 inches Baffle Spacing = 5 inches 1500 GAL AREA= 10.42 SF Baffle/Box Width = 62.5 inches Baffle Spacing = 24 inches 2-Year 50-Year (Pipes) 100-Year(Storage) Throat Qp Throat Vel Qp Throat Vel Throat Vel Size Structure Area SF ft/sec ft/sec Qp ft/sec 1000 GAL SG-4 8.611 2.92 0.34 1000 GAL SG-5 8.611 1.41 0.16 1000 GAL SG-6 8.611 1.31 0.15 1000 GAL SG-7 8.611 2.08 0.24 350 GAL I SG-8 1.424 0.15 0.10 Sagarra Sub. P2 - Storm Drain Calculations (PRIVATE) Seepage Bed Sizing - Infiltration Gallery#4 - Basin #4 Facility Type:Seepage Bed (ACHD BMP#20) Design Criteria: 1. Storage Chamber Design Criteria: 100-yr, 1-hr storm (intensity=0.96 in/hr) 2. Beds located outside of common lots shall be upsized by 25%for sediment storage 3. Bottom elevation of bed shall be 3-feet above the seasonal high ground water El. 4. Provide 1.5'thickness of ASTM C33 filter sand under rock(No storage credit for sand) 5. Drain rock shall be 1.5"-2" washed rock meeting ACHD specifications. 6. Max. drain rock thickness is 10-feet. 7. Seepage bed shall have 1.5' min. cover under sidewalks. Drainage Basin Characteristics: 2-yr, 1-hr 100-yr, 1-hr 2-yr Runoff 100-yr Tributary Basin Area Combined Runoff Storm Storm Volume Basins (SF) C-Value Volume Intensity Intensity (Cu. Ft.) (Cu. Ft.) BASIN 4 54700 0.9 0.26 0.96 1067 3938 0 0 0 0 54700 Total 1067 3938 Seepage Bed Sizing: The facility length is calculated below using the required storage volumes calculated above, the total facility rock width user input,the user input for facility depth, and the drain rock void ratio. Infiltration Rate of Underlying Soils: 8 in/hr Drain Rock Void Ratio: 0.40 (1) 100-yr Runoff Volume (Without Infiltration Credit): 3938 Cu Ft (2) Infiltration Volume for 1-hr duration: 573 Cu Ft Required Seepage Bed Capacity(1) - (2): 3365 Cu Ft Drain Rock Thickness: 10 FT Total Facility Width: 20.0 FT Min. Facility Length: 43.0 Ft Provided Seepage Bed Capacity(LxWxDxVoid Ratio): 3440 Cu Ft Is the provided Seepage Bed capacity greater that the required capacity? YES Per ACHD Policy,the facility shall be upsized by 25% if it's not located within a common lot. Is the facility located within a common lot (Y/N)? n Required Adjusted Facility Length: 54 FT Time Required to Infiltrate 90%of the 100-yr, 1-hr storm (48-hrs Max) Underlying soils infiltration rate: 8 In/hr Bottom Area of Seepage Bed: 1075 Sq. Ft. 100-yr, 1hr Storm Volume: 3938 Cu. Ft. Time Required to Infiltrate 90%of storm volume: 5.5 Hrs. OK Final Seepage Bed Dimensions and Volumes: Length Depth Vol (ft) Width (ft) (ft) (Cu Ft) Seepage Bed 54 20.0 10 4300 Total Capacity 4873 Sagarra Sub. P2 - Storm Drain Calculations (PRIVATE) Seepage Bed Sizing - Infiltration Gallery#5 - Basin #5 Facility Type:Seepage Bed (ACHD BMP#20) Design Criteria: 1. Storage Chamber Design Criteria: 100-yr, 1-hr storm (intensity=0.96 in/hr) 2. Beds located outside of common lots shall be upsized by 25%for sediment storage 3. Bottom elevation of bed shall be 3-feet above the seasonal high ground water El. 4. Provide 1.5'thickness of ASTM C33 filter sand under rock(No storage credit for sand) 5. Drain rock shall be 1.5"-2" washed rock meeting ACHD specifications. 6. Max. drain rock thickness is 10-feet. 7. Seepage bed shall have 1.5' min. cover under sidewalks. Drainage Basin Characteristics: 2-yr, 1-hr 100-yr, 1-hr 2-yr Runoff 100-yr Tributary Basin Area Combined Runoff Storm Storm Volume Basins (SF) C-Value Volume Intensity Intensity (Cu. Ft.) (Cu. Ft.) BASIN 5 26439 0.9 0.26 0.96 516 1904 0 0 0 0 26439 Total 516 1904 Seepage Bed Sizing: The facility length is calculated below using the required storage volumes calculated above, the total facility rock width user input,the user input for facility depth, and the drain rock void ratio. Infiltration Rate of Underlying Soils: 8 in/hr Drain Rock Void Ratio: 0.40 (1) 100-yr Runoff Volume (Without Infiltration Credit): 1904 Cu Ft (2) Infiltration Volume for 1-hr duration: 280 Cu Ft Required Seepage Bed Capacity(1) - (2): 1624 Cu Ft Drain Rock Thickness: 10 FT Total Facility Width: 15.0 FT Min. Facility Length: 28.0 Ft Provided Seepage Bed Capacity(LxWxDxVoid Ratio): 1680 Cu Ft Is the provided Seepage Bed capacity greater that the required capacity? YES Per ACHD Policy,the facility shall be upsized by 25% if it's not located within a common lot. Is the facility located within a common lot (Y/N)? n Required Adjusted Facility Length: 35 FT Time Required to Infiltrate 90%of the 100-yr, 1-hr storm (48-hrs Max) Underlying soils infiltration rate: 8 In/hr Bottom Area of Seepage Bed: 525 Sq. Ft. 100-yr, 1hr Storm Volume: 1904 Cu. Ft. Time Required to Infiltrate 90%of storm volume: 5.4 Hrs. OK Final Seepage Bed Dimensions and Volumes: Length Depth Vol (ft) Width (ft) (ft) (Cu Ft) Seepage Bed 35 15.0 10 2100 Total Capacity 2380 Sagarra Sub. P2 - Storm Drain Calculations (PRIVATE) Seepage Bed Sizing - Infiltration Gallery#6 - Basin #6 Facility Type:Seepage Bed (ACHD BMP#20) Design Criteria: 1. Storage Chamber Design Criteria: 100-yr, 1-hr storm (intensity=0.96 in/hr) 2. Beds located outside of common lots shall be upsized by 25%for sediment storage 3. Bottom elevation of bed shall be 3-feet above the seasonal high ground water El. 4. Provide 1.5'thickness of ASTM C33 filter sand under rock(No storage credit for sand) 5. Drain rock shall be 1.5"-2" washed rock meeting ACHD specifications. 6. Max. drain rock thickness is 10-feet. 7. Seepage bed shall have 1.5' min. cover under sidewalks. Drainage Basin Characteristics: 2-yr, 1-hr 100-yr, 1-hr 2-yr Runoff 100-yr Tributary Basin Area Combined Runoff Storm Storm Volume Basins (SF) C-Value Volume Intensity Intensity (Cu. Ft.) (Cu. Ft.) BASIN 5 24500 0.9 0.26 0.96 478 1764 0 0 0 0 24500 Total 478 1764 Seepage Bed Sizing: The facility length is calculated below using the required storage volumes calculated above, the total facility rock width user input,the user input for facility depth, and the drain rock void ratio. Infiltration Rate of Underlying Soils: 8 in/hr Drain Rock Void Ratio: 0.40 (1) 100-yr Runoff Volume (Without Infiltration Credit): 1764 Cu Ft (2) Infiltration Volume for 1-hr duration: 256 Cu Ft Required Seepage Bed Capacity(1) - (2): 1508 Cu Ft Drain Rock Thickness: 10 FT Total Facility Width: 12.0 FT Min. Facility Length: 32.0 Ft Provided Seepage Bed Capacity(LxWxDxVoid Ratio): 1536 Cu Ft Is the provided Seepage Bed capacity greater that the required capacity? YES Per ACHD Policy,the facility shall be upsized by 25% if it's not located within a common lot. Is the facility located within a common lot (Y/N)? n Required Adjusted Facility Length: 40 FT Time Required to Infiltrate 90%of the 100-yr, 1-hr storm (48-hrs Max) Underlying soils infiltration rate: 8 In/hr Bottom Area of Seepage Bed: 480 Sq. Ft. 100-yr, 1hr Storm Volume: 1764 Cu. Ft. Time Required to Infiltrate 90%of storm volume: 5.5 Hrs. OK Final Seepage Bed Dimensions and Volumes: Length Depth Vol (ft) Width (ft) (ft) (Cu Ft) Seepage Bed 40 12.0 10 1920 Total Capacity 2176 Sagarra Sub. P2 - Storm Drain Calculations (PRIVATE) Seepage Bed Sizing - Infiltration Gallery#7 - Basin #7 Facility Type:Seepage Bed (ACHD BMP#20) Design Criteria: 1. Storage Chamber Design Criteria: 100-yr, 1-hr storm (intensity=0.96 in/hr) 2. Beds located outside of common lots shall be upsized by 25%for sediment storage 3. Bottom elevation of bed shall be 3-feet above the seasonal high ground water El. 4. Provide 1.5'thickness of ASTM C33 filter sand under rock(No storage credit for sand) 5. Drain rock shall be 1.5"-2" washed rock meeting ACHD specifications. 6. Max. drain rock thickness is 10-feet. 7. Seepage bed shall have 1.5' min. cover under sidewalks. Drainage Basin Characteristics: 2-yr, 1-hr 100-yr, 1-hr 2-yr Runoff 100-yr Tributary Basin Area Combined Runoff Storm Storm Volume Basins (SF) C-Value Volume Intensity Intensity (Cu. Ft.) (Cu. Ft.) BASIN 5 39020 0.9 0.26 0.96 761 2809 0 0 0 0 39020 Total 761 2809 Seepage Bed Sizing: The facility length is calculated below using the required storage volumes calculated above, the total facility rock width user input,the user input for facility depth, and the drain rock void ratio. Infiltration Rate of Underlying Soils: 8 in/hr Drain Rock Void Ratio: 0.40 (1) 100-yr Runoff Volume (Without Infiltration Credit): 2809 Cu Ft (2) Infiltration Volume for 1-hr duration: 403 Cu Ft Required Seepage Bed Capacity(1) - (2): 2406 Cu Ft Drain Rock Thickness: 10 FT Total Facility Width: 11.0 FT Min. Facility Length: 55.0 Ft Provided Seepage Bed Capacity(LxWxDxVoid Ratio): 2420 Cu Ft Is the provided Seepage Bed capacity greater that the required capacity? YES Per ACHD Policy,the facility shall be upsized by 25% if it's not located within a common lot. Is the facility located within a common lot (Y/N)? n Required Adjusted Facility Length: 69 FT Time Required to Infiltrate 90%of the 100-yr, 1-hr storm (48-hrs Max) Underlying soils infiltration rate: 8 In/hr Bottom Area of Seepage Bed: 756 Sq. Ft. 100-yr, 1hr Storm Volume: 2809 Cu. Ft. Time Required to Infiltrate 90%of storm volume: 5.6 Hrs. OK Final Seepage Bed Dimensions and Volumes: Length Depth Vol (ft) Width (ft) (ft) (Cu Ft) Seepage Bed 69 11.0 10 3025 Total Capacity 3428 Sagarra Sub. P2 - Storm Drain Calculations (PRIVATE) Seepage Bed Sizing - Infiltration Gallery#8 - Basin #8 Facility Type:Seepage Bed (ACHD BMP#20) Design Criteria: 1. Storage Chamber Design Criteria: 100-yr, 1-hr storm (intensity=0.96 in/hr) 2. Beds located outside of common lots shall be upsized by 25%for sediment storage 3. Bottom elevation of bed shall be 3-feet above the seasonal high ground water El. 4. Provide 1.5'thickness of ASTM C33 filter sand under rock(No storage credit for sand) 5. Drain rock shall be 1.5"-2" washed rock meeting ACHD specifications. 6. Max. drain rock thickness is 10-feet. 7. Seepage bed shall have 1.5' min. cover under sidewalks. Drainage Basin Characteristics: 2-yr, 1-hr 100-yr, 1-hr 2-yr Runoff 100-yr Tributary Basin Area Combined Runoff Storm Storm Volume Basins (SF) C-Value Volume Intensity Intensity (Cu. Ft.) (Cu. Ft.) BASIN 5 2780 0.9 0.26 0.96 54 200 0 0 0 0 2780 Total 54 200 Seepage Bed Sizing: The facility length is calculated below using the required storage volumes calculated above, the total facility rock width user input,the user input for facility depth, and the drain rock void ratio. Infiltration Rate of Underlying Soils: 8 in/hr Drain Rock Void Ratio: 0.40 (1) 100-yr Runoff Volume (Without Infiltration Credit): 200 Cu Ft (2) Infiltration Volume for 1-hr duration: 30 Cu Ft Required Seepage Bed Capacity(1) - (2): 170 Cu Ft Drain Rock Thickness: 10 FT Total Facility Width: 5.0 FT Min. Facility Length: 9.0 Ft Provided Seepage Bed Capacity(LxWxDxVoid Ratio): 180 Cu Ft Is the provided Seepage Bed capacity greater that the required capacity? YES Per ACHD Policy,the facility shall be upsized by 25% if it's not located within a common lot. Is the facility located within a common lot (Y/N)? n Required Adjusted Facility Length: 11 FT Time Required to Infiltrate 90%of the 100-yr, 1-hr storm (48-hrs Max) Underlying soils infiltration rate: 8 In/hr Bottom Area of Seepage Bed: 56 Sq. Ft. 100-yr, 1hr Storm Volume: 200 Cu. Ft. Time Required to Infiltrate 90%of storm volume: 5.3 Hrs. OK Final Seepage Bed Dimensions and Volumes: Length Depth Vol (ft) Width (ft) (ft) (Cu Ft) Seepage Bed 11 5.0 10 225 Total Capacity 255 SAND AND TANK RIM EL 18"HALF DRAIN ROCK PERF PIPE IE TOP OF BOTTOM OF EXISTING SEASONAL TOP OF 18" BOTTOM OF DEPTH LOWEST SEEPAGE MINUS TO TOP OF GROUND EL. HIGH PERF PIPE FROM COVER TANK LOWEST LOWEST FG TOP OF 18"PERF FG GREASE SIZE TANK RIM EL.OVER LOWER PERFORATED THICKNESS DRAIN DRAIN ROCK PIPE TO TO TOP OF TRAP # BED# (GAL) EL. BED. BAFFLE EL LOWER PIPE IE. (FT) DRAIN ROCK ROCK EL. EL. AT SEEPAGE GROUND TO TOP OF BOTTOM OF ROCK TO ROCK CHECK BAFFLE EL (FT) BED WATER EL. ROCK(FT) ROCK(FT) GW SG-4 4 1000 2579.79 2579.65 2573.89 5.90 2572.64 10.00 5.01 2577.65 2567.65 2579.68 2559.68 3.51 4.99 7.97 2.00 OK SG-5 5 1000 2580.13 2580.12 2575.82 4.31 2574.57 10.00 3.55 2578.12 2568.12 2578.79 2558.79 2.05 6.45 9.33 2.00 OK SG-6 6 1000 2579.33 2579.35 2574.07 5.26 2572.82 10.00 4.53 2577.35 2567.35 2579.34 2559.34 3.03 5.47 8.01 2.00 OK SG-7 7 1000 2578.99 2579.03 2572.68 6.31 2571.43 10.00 5.60 2577.03 2567.03 2579.38 2559.38 4.10 4.40 7.65 2.00 OK SG-8 8 350 2579.46 2579.33 1 N/A N/A 2575.46 10.00 1.87 2577.33 1 2567.33 1 2579.18 1 2559.18 1 0.37 1 8.13 1 8.15 2.00 OK Keyed Notes 0 1. 48" DIA. CONCRETE STORM DRAIN CATCH MANHOLE PER ACHD STANDARD SUPPLEMENTAL DRAWING SD-611 (SEE SDA). � N: 727584.1419 '\E: 2451879.8209 rr - - - 2. 350 GAL SAND AND GREASE TRAP -AMCOR DB-350 -(SEE 1/SD.5). 6"IE: 2578.00 /r / /' SDMH-4E 3. 1000 GAL SAND AND GREASE TRAP PER CURRENT ACHD STORM WATER 8 rr / RIM EL:2579.20 / DESIGN GUIDELINES BMP#1 (SEE SHEET SDA AND SEE DETAIL 2/SD.3). N:727561.2189 4. SEEPAGE BED PER CURRENT ACHD STORM WATER DESIGN GUIDELINES r Q E:2451967.3143 BMP#20 (SEE SHEET SD.5 AND SEE DETAIL 1/SD.3). CORNER MARKERS ' c /N. 9 �, / 12 IE OUT:2575.70(SW) ARE NOT REQUIRED FOR PRIVATE SEEPAGE BEDS. N r/ d� �r / i/ - _ - gx / _ SDMH-4D 5. GROUND WATER OBSERVATION WELL PER ACHD SUPPLEMENTAL STORM DRAIN (PRIVATE) ' RIM EL:2579.97 ��- gW Iti` ° DRAWINGS SD-627 . LOCATE r SHEETS 1 &2 .4 4E E N:727544.6367 . -/ ( ) - SEE SHEET SDA). ) /� o a : o w / ° LL MONITORING WELLS IN ACCORDANCE WITH CURRENT ACHD o zo ao / c - C E: 2451919.9609 ! 8� 00I0 - STORMWATER GUIDELINES BMP#4 SHEET 2. FEET F / 12" IE IN:2575.46(NE) VG @ / 8 m� / N:727481.5943 N:727543.8288 /�'ti O / 35Q 6. SOLID WALL 18 DIA.ADS N12 DUAL WALL PIPE BETWEEN STRUCTURE y �= /c1' �o� 12" IE OUT:2575.36(S) SCR 1 ,$ E:2451774.7277 E:2451838.5071 s / 12 SO �`° ° / AND SEEPAGE BED (NON-PERORATED). / _ / 6"IE: 2577.42 00: r- q6���"� 12 u' 6"IE: 2578.25 L) t i/i r r I Q 7. CAP END. m '. �oNoao ��� 8. STANDARD 4" TRAFFIC RATED CLEANOUT PER ISPWC SD-506A - (SEE ��� / / Q v z O SHEET SD.5). - // LL �J. ♦ / =moo a / /j/ // /JG ° ` ♦ I V 9. STORM DRAIN SERVICE -(SEE 3/SD.3). �� , / / a _ s o� '� �. . ♦ I 1 , , Oho i _ m N. 727503.5158 / /OQ- / CD ♦' U �� �� 9 //E. 2451797.1933 y / � �� , M �Q� ♦ Notes � N: 727441.5479 6"IE: 2576.84/ / �Q r M 0� 04 I Q /E:2451733.6871 e Z r �� 6"IE: 2577.66 1. SEE SHEET THE PROJECT GEOTECHNICAL REPORT FOR EARTHWORK P � o REQUIREMENTS. �� ' �a I nn 2. ALL PIPE FITTINGS INCLUDING BUT NOT LIMITED TO BENDS, 0 o , SG# TRANSITIONS, TEES, AND REDUCERS ARE NOT CALLED OUT ON THE r ��� / / / 9 CONTACT DMINE 1000 GAL S&G TRAP I PLANS AND ARE INCIDENTAL TO THE STORM DRAIN SYSTEM. / Q�� // �' ,' 48-HOURS O �0 12 IE IN:2574.14(E) q�� o N I CONTRACTOR SHALL PROVIDE ALL FITTINGS INCLUDING BUT NOT / Q /j i o. ., / / BEFORE DlcaNG r 12 IE IN:2574.14(W) - I , LIMITED TO BENDS TRANSITIONS TEES AND REDUCERS AS REQUIRED / Q` /� / / / 1_gpp_�2_1r�r 6 6" IE IN:2574.64(W) I ' �? ,L TO COMPLETE THE STORM DRAIN SYSTEM. ALL FITTINGS AND PIPING / C� �� / /0\0 8 TOP OF LOWER BAFFLE EL:2573.89 -� I /� � //.' O e o SHALL BE SDR 35 PVC UNLESS SPECIFICALLY NOTED TO BE C-900 PVC - oAG� 18" IE OUT�2572.64(S) �^ FITTINGS JOINING C-900 PVC PIPE SHALL BE 900 PVC. // / / v_O / // /A 9 3 AL FINISHED� ° •° '` ' ' �' -00 -------- ° 27404.2951 ADJUST STRUCTURE FRAMES AND COVERS TO MATCH FIN / �� N 7 O/ RIM:2579.79"_ o /�' � , � i M N ° N GRADE ELEVATIONS AND SLOPE. (SEE GRADING PLANS). / E:2451695.5095 / g0 / �� RIM:2579.79 N �� 6"IE: 2577.12 / �� , M U w 4. ALL TRENCHING AND BACKFILL FOR STORM DRAIN CONSTRUCTION / r � i 21.17 LF 12 SDR 35 PVC @ 3.26%_ - , / J Q SHALL MEET STRUCTURAL FILL SPECIFICATIONS AS PROVIDED IN THE / ° 8 /�4� g0 � J I r SDMH-4A 48 29 LF 12"SD �M PROJECT GEOTECHNICAL REPORT, AND THE CURRENT EDITION OF THE 5.73 LF 6"SDR 35 PVC @ 1.2/o // N / RIM EL:2579.71 1 R 35 PVC @ 2.1751, 3 I ISPWC. /- ' / - oe Z N:727465.6212 / 2SD 1 / // N: 727398.5621 r 'b W O - 8 �� I I SDMH-4C - 5. PROVIDE CONCRETE COLLARS FOR ALL MANHOLES, AND CLEANOUTS // / E: 2451695.3595 / ,� U) D _ E:2451834.1674 1 / I Q Z SD . RIM EL:2579.28 I ' WITHIN PAVED LOCATIONS PER THE ISPWC. // aw i 6"IE: 2577.05 9 � 6" IE IN:2576.33(NW) N:727453.9714 - / °° �� 2 - - b ° g °' N:727455.2927 I 6. TEMPORARY INLET PROTECTION SHALL BE PROVIDED AND MAINTAINED / �" i °° 6 IE IN:2575.69(SE) E:2451863.4376 O� b / N:727380.6127 st 12"IE OUT:2575.19 E ' 6"IE: 2575.83 1 E:2451911.4822 WITHIN ALL STORM DRAIN INLETS THROUGHOUT THE DURATION OF �� �� m O _ = 12"IE IN:2574.93(N) PROTECTION E:2451670.1196 roe i Q Lu -, CONSTRUCTION. TEMPORARY INLET SHALL BE REMOVED �/ 6 IE: 2577.56 �'O R' 1 U �j 23.95 LF 6"SDR 35 PVC @ 4.97% 12" IE IN:2574.93(S) r UPON COMPLETION OF ALL LANDSCAPING FINAL SITE CLEANUP AND ew / r �` 1 Q 1 12" IE OUT:2574.83E s % ' �:,9 O I o � � ° PARKING LOT SWEEPING. a f � . ° / i 42.69LF6 SDR 35 PVC @1.0% I I _,-� I v � ' Q / / ��'C' �'S U CD J� - - - / e �O F- - / Q ' . . N:727411.2$72 ;� �� SEEPAGE I � � _ _ _ __ aw I /� ,�, o � \• �P� �b (n 36.78 LF 12 SDR 35 PVC @ 1.85/o / / r c�0 / • 1 / w 1 w E:2451863.0396 a l BED#4 „ ° I I - -- - aw� / i / 9 / ° 0 / 4 - = z o � �� 6 WYE .� � � ° �� � w � o � � � I I I aw�sw T� /' / w w ° ---- - --- I � � 6�� 6'41E 2576.26(NW)` ° _ u�i . Bw aw Bw 3<< ,w aw fi sw� w �w aw Bw� - ° //' / SDMH-SA- �� BED#5 // ° 7 o O a „ ( ) SDMH-4B - - - - - - - - - - i- i / �99.61 LF 6 SDR 35 PVC @ 1. 1% �o RIM EL.2579.68 4 IE: 2576.26(SW&SE) 5` ` - - `� SS FNG • ° �, • ° i � -RIM EL:2579.11 -�-i - - � � 6 � � N:727362.7605 � � � o -- / E:2451728.4038 3 g CASTE /f/ ° 12.53 LF 4 SDR 35 PVC @ 1.9/0 1 N:727414.5139 I � � � �� � /�9 i / N:727402.8336 4j° W E:2451911.1020 / 6 IE IN:2576.58(NW)� 12"IE OUT:2575.61 N 5� / 12"IE OUT:2576.18 SE ° E:2451853.7946 1 gc Q I � I i i _- ( ) O I - N:727332.2364� -� ° 6 ��> / 4��IE: 2576.50 s I = - __ -- - _ - �E:2451580.4112 - /�50 �, / 12"SD 50% 6 IE: 2575.56 /� 21.26 LF R 35 PVC @ 0. 8 21-23 �O o i/ // / . RIM:2580.13 qT P 23.47 LF 4"SDR 5 PVC @ 1.0% 5.16' FG:2579.65 a I 0` �� N:727321.3484 89.58 LF 6 SDR 35 PVC @ 1.0/° _ 9� / , ° �� q,� ,� 1 'pp F OF 20 00 Z I ) E:2451494.9167 8 ---------- - 000e J ex I eso 6"IE: 2574.66 - - - -_ - (0- N: 8 -� ,, q J E 727387.8214 $ W I I _--r_-_- -_-_ - --- - --- D- - °y 1 /Q FG:2580.12 E: 2451862.8208 Z I ���° 7 / / -- - 6SD 6S - - , 5� \ M , • � � o SG#5 / • M �, 4, RIM:2580.13 . � • . 3W - 4"IE: 2576.50 � 1000 GAL S&G TRAP �• �• • • 12" IE IN:2576.07(NW) • . I \ 37.16 LF 6 SDR 35 PVC 1.0/o � a 1 � �� TOP OF LOWER BAFFLE EL:2575.82 /� D • �• �• 0 I I r ro of 1 I I I // / . 18 IE OUT. 2574.57( ) Q• 574 7 N E / • . . . A _ _ I -_ I �' • col �� ., e �U� � - I co 8 / W° `* 8 / / O M N: 727247.0963 / �� w 1 N:727284.5646 / Q �o M ° o E.2451685.4705 - N: 727280.4816 I E:2451489.6073 / �W s 6 IE: 2574.29 35.24 LF 6"C-900 PVC @ 1.0% y/ .° 4"IE: 2576.50 N: 727236.6806 N E:2451443:8312 a o / � E:2451685.3554 , -- <� / - 8,�X 4"TEE o - --` 57 .75 ° 8S -------- LLI 8S il� 8"X4"RED N&W --� N: 727255.7535 8S a 10 4 LF 4"SDR 35 1 °/ ( ) I > 8 !_ E: 2451509.9037 ° S PVC @ 1.3 0 8"IE:2575.15 z� Q ° 4"IE: 2575.32(N&W) Z ' w 6" IE: 2573.93 \ \� � oo 2 00' ni Q o� `° 0 21.97 LF 4"SDR 35 PVC @ 5.4%�f 8 s< 1i 40.42 LF 6 SDR 35 PVC @ 1.0/o C7 0 I I p. N:727224.4617 og N: 727215.5640 8 E:2451685.2204 z �z W co E:2451505.6333 8"X 4"TEE o� m v 6"IE: 2573.52 8"IE:2574.91 Ln > Ix X N:727223.6800 af W W z 0 Z _ M Q 4"IE:2573.52 N: 727230.1384 4"IE: 2575.08(E) E:2451755.9684 N= LL E:2451523.6731 N:727236.9233 8 �N SG#8 0 s 00 C) 4" IE: 2575.50 E:2451663.3878 4 IE: 2576.50 SDMH-5A Z - 70.75 LF 4"SDR 35 PVC 2. ° `W DB-350 GAL y RIM EL:2578.49 4 IE: 2576.50 @ 0/o ,o r RIM EL: 2579.46 a` Q O 23.19 LF 4"SDR 35 PVC 1.0% 4SD 4SD 4SD N � N '1 �° N:727198.4240 �' @ ---- I J O N: 451433.2367 a' 12 IE OUT:2574.49 NE Z 11 12.22 LF 8 SDR 35 P 405 9.40 LF 6 SDR 35 PVC @ 1.0% ° SEEPAGE o� N E: 2451433.2367 9( ) VC @ 2.0/° o RIM:2579.51 BED#6 xK TOP OF BOX EL:2577.96/ �' v 6 4 00 6"IE IN:2575.83(N) . 3 .°. . SEEPAGE5 o s " 6"IE IN:2575.83(S) / 1 °°° BED#7 4.53 LF 1 DR 35 PVC @2.0/o 2 2"S ° 3 18"IE OUT: 2575.46(SW) n -__ �� w a 9 um w ------ O o0 W IV N 7271999328 5 ----- o �3 / - FG:2579.03 - - �- - _ - - - - o z __ � DIRECTOR L FG: - - - -- 08 NO 6 _ .• e � - - - PRIVATE - E: 2451684.9494- - - � - 00 8" IE: 2574.42 900/ 5 �Lj,r 16.32 LF 12"C- PVC @ 2 - - -� - - 5.12 LF 8"SDR 35 PVC @ 2.0% 40.00' 25ao W SEEPAGE �_ BED#8 / I 7% v z_ p @ /o co - �, 0) 1 0 LF 6 SDR 35 PVC @ 1.0 FG: 5 9.45 - / 14 2 .7 e I 69.00 Of I I 10�00 GAL S&G TRAP � i i � > z } � � � Y � M I I I 8 IE IN:2574.32(W) I I I o / a m z m RIM 2578.99 I I I I I TOP OF LOWER BAFFLE EL:2574.07 I I co acn N N z FG:2579.33 0 / I SG#7 I I 18"IE OUT:2572.82(NE) I I I � w a of- .. Q Z N °I RIM:2579.09 I 1000 GAL S&G TRAP I I I I I I I ° w 0 I I I I I RIM:2579.33 0- 0- - - N: 727165.1294 8 12"IE:2572.93(W) I I I - I I Z N E:2451431.5888 I a 6"IE IN:2573.43(N) I I JOB NUMBER: 6"IE: 2576.05 I I I I I �o� IDB2355 m L- - °I °, TOP OF LOWER BAFFLE EL:2572.68 I _ I 18"IE OUT:2571.43(E) I I I I `'�G� �NO Q DATE: 8-21-23 QQ �G TT-------- ` SHEET NUMBER: � 10 SDm2 w 'w Q w v/ F W SEEPAGE BED WIDTH=SEE PLANS o Y 24" DIA. CAST IRON 24" DIA. CAST IRON ROADWAY SECTION RING AND COVER < RING AND COVER OR LANDSCAPE PLANTER J CONCRETE COLLAR PER ISPWC SD-616 (REQ. IN ALL 18"DIAMETER DUAL WALL ADS z PERFORATED (SEE PLANS) z_ o PAVED AREAS. NOT REQUIRED WHERE SAND AND PIPE @ 0.0%(SEE PLAN FOR PIPE SIZE). PIPE w GREASE TRAP LIDS ARE LOCATED COMPLETELY SHALL BE PERFORATED AS SHOWN ON THE PIPE > 0O 12" WITHIN A PLANTER PERFORATION SCHEDULE INCLUDED ON THIS DETAIL SHEET-CAP END. STRUCTURAL FILL BETWEEN BOTTOM OF ROAD SECTION p5° 4sa a PLACE WOVEN GEOTEXTILE FABRIC AND TOP OF DRAIN ROCK FOR BEDS WITHIN PAVED AREAS COMPACTED TO 95%MAX DRY DENSITY PER ASTM D1557 ON PAVEMENT SECTION SUBGRADE FINISHED GRADE 4 a a a Q GROUT GROUT OVER SAND AND GREASE TRAP. 318"DIA. o o Q o GROUT"" GROUT FABRIC SHALL EXTEND A MINIMUM OF CONCRETE GRADE RING A � D PERFORATION vo 00 RISER SECTION AS R Q Q 6-FEET BEYOND THE SAND AND pQV GROUT GROUT 18"PIPE PERF.EL / w W (12" MAX GRADE RING H���.�T� Q a W GREASE TRAP ON ALL SIDES. (SKAPS TOP OF SEE PLAN FOR PIPE SIZE m �.aD� a GEONET TN220 OR APPROVED DRAIN ROCK / D D EQUAL GEOTEXTILE FABRIC IS NOT Q a 5.00'NON.PERF. o 00 0 0 0 0 o y o o / / GRO pQ° )0 -6 0 0 0 0 0 o W o PERFORATED PIPE IE TO o / ur0 PIPE(TYP.) REQUIRED UNDER LANDSCAPE 1 �� �a TOP OF DRAIN ROCK v //// o Q Q AREAS. N x w o 0 0 0 0 0 o Oo // IMPERMEABLE SILTS AND CLAY D4 D4 8 " Q GROUT NON.PERF. o a w //O w/ � )/D\_ 18"z PERFORATED PIPE IE.- // / pQ7 D pQ� ' PIPE 5.0'INTO s `� Z ? SEE PLAN FOR PIPE SIZE AND / / 18"DIA.DUAL 4 A Q 4 a d C s Y / O O O O O O O O O� O / / Q o Q SEEPAGE BED L Q Z O O O O O O O O O O ' C PLACEMENT IN BED / WALL ADS PIPE aD� a O +, o o E 3 w �� INSTALL 6 OZISY NON-WOVEN GEOTEXTILE FABRIC (SEE PLAN FOR PIPE SIZE BACKFILL D D IL V _ o o�o�o 0 0�0�0 0�0�0 0�0�0�0�0 0 ) Q�p p a Z EL B SEE NOTE 4 _ _ >- 0no �o 0 0 0 0 o AASHTO M288 CLASS 2 ON TOP&SIDES SAND AND GREASE 1 / 4 a Q a PIPE TOP OF LOWER D� / TRAP WITH CHIPS Q Q _ 2 CLEAN ANGULAR DRAIN ROCK -s O�O�O�O�OUOUOUOUOUO�S�5_0 O�O O // DIA PERFORATION IN D D p E o . T- o BOTTOM OF o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 / aD aD a I N BAFFLE EL. F a� 0 e y DRAIN ROCK / BOTTOM OF DRAIN ROCK/ VALLEYS OF CORRUGATED Qp D pQp EL A s TOP OF ASTM C33 SAND PIPE. 5 EA. Q a EL D O Q _ _ - t- �D ASTM C33 FILTER SAND D� aD17 o aD L a BOTTOM OF ASTM C33 SAND �� pQ D pQp INLET SIDE PIPE INVERT o N N w o 18 PERF. PIPE o (GROUT) d c 1 a 2 WATER TIGHT SEAL Q a a EL C 20' �, O z PERF RATED 18" HDPE 9 a DESIGN INFILTRATION RATE=8.0"PER HOUR p Q PIPE 0.0% SEE a. - M Oa as a� a (ALL SEEPAGE BEDS) Oa as PERFORATION Da �DaD . O C @ ( mw a� o DDDDD�DDD ;� D� D DO D EXISTING POORLY GRADED GRAVEL SCHEDULE Q a Do N SOLID WALL INFILTRATION GALLERY 1 000 GALLON SAND AND OUTLET SIDEEn GROUND WATER EL-GREATER THAN 20.00 FEET /B>GS a�a�DOa Oa Oa <ADS HDPE SECTION DETAIL P63 � GREASE TRAP , aD CPIPE @ 0.0% aaD ap�a�D a�D aaDaD D4D ap� SEEPAGE BED p�aD p�aDa p�aDa p�aDa p�aDa p�aDa p�aDa p�aDa p��DQap aDa p �OC ' D� ACHD SEEPAGE BEDS s CONTACT DMNE 24" DIA. CAST IRON PLACE TRAPS ON 8" THICKNESS OF CHIPS 48-HOURS RING AND COVER OVER NATIVE UNDISTURBED EARTH BEFORE DIGCgNC TANK RIM EL PERF PIPE IE EXISTING SEASONAL TOP OF 18" BOTTOM OF DEPTH NOTES 1'800'342'`� SAND AND TANK LOWEST LOWEST FG TOP OF 18" HALF DRAIN ROCK TOP OF BOTTOM OF 18" PERF LOWEST FG GREASE SEEPAGE SIZE TANK RIM EL. OVER LOWER MINUS PERFORATED THICKNESS TO TOP OF DRAIN DRAIN ROCK GROUND EL. HIGH PERF PIPE PIPE TO FROM TO TOP OF COVER � STORM DRAIN 4 1. MUST BE RATED FOR HS-25 TRAFFIC LOADS BED # LOWER DRAIN ROCK AT SEEPAGE GROUND TO TOP OF ROCK TO CHECK JOINT a 2. INTERIOR DIMENSIONS OF TRAP MUST BE A MINIMUM OF 48" X 24" AT THE THROAT LOCATION. TRAP # (GAL) EL. BED. BAFFLE EL BAFFLE EL PIPE IE. (FT) (FT) ROCK EL. EL. BED WATER EL. ROCK (FT) BOTTOM OF GW ROCK ROCK (FT) 4 3. THE DETAIL ABOVE SHOWS AN VALLEY PRECAST 1,000 GALLON SAND & GREASE TRAP. N MONOLITHIC d 1 4. THE SAND AND GREASE TRAPS SHALL BE SET SO THAT THE TOP OF LOWER BAFFLE ELEVATION, THE IE'S PIPES J Lu CONCRETE COLLAR ENTERING, AND THE PIPES EXITING ARE IN ACCORDANCE WITH THE PROJECT PLANS AND NOTE 9 BELOW. J Q 2 SG-1 1 1000 2578.21 2577.95 2574.31 3.90 2573.06 10.00 2.89 2575.95 2565.95 2578.86 2558.86 1 .39 7.11 7.09 2.00 OK PER ISPWC SD-616 5. SAND AND GREASE TRAP COVERS SHALL MATCH THE FINISHED GRADE ELEVATION AND SLOPE. STORM DRAIN 6. SOLID COVERS SHALL HAVE THE WORDS "STORM DRAIN" CAST INTO THE LID. LU O z SG-2 2 1000 2579.14 2578.88 2575.25 3.89 2574.00 10.00 2.88 2576.88 2566.88 2579.75 2559.75 1 .38 7.12 7.13 2.00 OK U) 0 z 7. DO NOT CONSTRUCT CONCRETE COLLARS FOR SAND AND GREASE TRAP COVERS LOCATED COMPLETELY 2 U) Q 24" DIA. CAST IRON a WITHIN LANDSCAPE AREAS. 0 0 SG-3 3 1000 2578.89 2578.42 2574.79 4.10 2573.54 10.00 2.88 2576.42 2566.42 2579.81 2559.81 1 .38 7.12 6.61 2.00 OK RING AND COVER 8. H<1FT USE GRADE RINGS (TYP.) C w CONCRETE COLLARS ARE NOT 1-FT < H <= 2-FT USE 24" DIA. RCP RISER; PRIVATE SEEPAGE BEDS REQUIRED WHEN LID IS LOCATED 2-FT < H <= 10-FT USE 48" MANHOLE CONE AND 48" RISERS. � � COMPLETELY WITHIN A PLANTER AREA g EL. A> EL. B BY 0.10 MIN; EL. D < EL. B BY 0.85 MIN.; EL. C < EL. B BY 0.50 MIN. Q LU 10. MANHOLE FRAME AND COVER PER ISPWC SD-617. Q ACHD RIGHT-OF-WAYCO BOTTOM OF 11. BOX MANUFACTURER SHALL MARK FLOW DIRECTION AND LABEL INLET AND OUTLET ON SIDE OF BOX. ~ TANK RIM EL PERF PIPE IE EXISTING SEASONAL TOP OF 18" DEPTH MONOLITHIC w LU SAND AND TANK LOWEST LOWEST FG TOP OF 18 HALF DRAIN ROCK TOP OF BOTTOM OF 18 PERF LOWEST FG 12. SEE ACHD STORMWATER DESIGN GUIDELINES BMP#1 "SAND AND GREASE TRAP" FOR ADDITIONAL z o SEEPAGE MINUS TO TOP OF GROUND EL. HIGH PERF PIPE FROM COVER � 0 GREASE SIZE TANK RIM EL. OVER LOWER PERFORATED THICKNESS DRAIN DRAIN ROCK PIPE TO TO TOP OF CONCRETE COLLARS REQUIREMENTS. O o BED # LOWER DRAIN ROCK AT SEEPAGE GROUND TO TOP OF ROCK TO CHECK TRAP # (GAL) EL. BED. BAFFLE EL BAFFLE EL PIPE IE. (FT) (FT) ROCK EL. EL. BED WATER EL. ROCK (FT) BOTTOM OF GW ROCK ROCK (FT) �SS\0AL ENG/ G\STE SG-4 4 1000 2579.79 2579.65 2573.89 5.90 2572.64 10.00 5.01 2577.65 2567.65 2579.68 2559.68 3.51 4.99 7.97 2.00 OK 1 ,000 GALLON SAND AND GREASE (S & G) TRAP 2 3 SG-5 5 1000 2580.13 2580.12 2575.82 4.31 2574.57 10.00 3.55 2578.12 2568.12 2578.79 2558.79 2.05 6.45 9.33 2.00 OK $D.3 J9,8-21-23 F_ - A � OF R C�S�� SG-6 6 1000 2579.33 2579.35 2574.07 5.26 2572.82 10.00 4.53 2577.35 2567.35 2579.34 2559.34 3.03 5.47 8.01 2.00 OK E W SG-7 7 1000 2578.99 2579.03 2572.68 6.31 2571.43 10.00 5.60 2577.03 2567.03 2579.38 2559.38 4.10 4.40 7.65 2.00 OK W > � •W W . . . • J O J J W N 1 •• •• • SG-8 8 350 2579.46 2579.33 N/A N/A 2575.46 10.00 1 .87 2577.33 2567.33 2579.18 2559.18 0.37 8.13 8.15 2.00 OK 2.00' 1.00' ' �• �• FLOW - FLOW - FLOW MMON LOT BUILDING LOT PVC THREADED CAP PERCOLATION TEST REQUIRED AT EACH SEEPAGE BED NOTES: N Keyed Notes O SEEPAGE BED LOCATION: 1. CONTRACTOR SHALL NOTIFY ENGINEER IMMEDIATELY IF GROUNDWATER O IS ENCOUNTERED AT AN ELEVATION HIGHER THAN THE BOTTOM COMMON LOT N 6"X 4"WYE 6"SDR 35 PVC o 7 1. NON WOVEN FILTER FABRIC ON TOP, ENDS, AND ALL SIDES OF 1. THE DESIGN PERCOLATION RATE FOR THE SEEPAGE BED INFILTRATION ELEVATION OF THE LINED SEEPAGE BED; OR, WITHIN 3-FEET OF THE FINISHED I N O FACILITIES IS 8 INCHES/HR. UNDER DIRECTION OF THE OWNER'S BOTTOM ELEVATION OF AN UNLINED SEEPAGE BED. SEEPAGE BED. o GRADE W 2Z GEOTECHNICAL REPRESENTATIVE, CONTRACTOR SHALL CONDUCT A M 4"SDR 35 PVC @ 2.0% o FO PERCOLATION TEST TO BE WITNESSED BY THE OWNER'S 2. ALL GEOTEXTILE FABRIC SEAMS SHALL OVERLAP 1-FOOT MINIMUM, 1 / �N N GEOTECHNICAL REPRESENTATIVE &ACHD. ACHD IS NOT REQUIRED TO UNLESS OTHERWISE DIRECTED BY THE MANUFACTURER. _ _ PROPERTY LINE 7/n/77�\ // OWITNESS PERCOLATION TESTS FOR PRIVATE INFILTRATION FACILITIES. CONTRACTOR SHALL PROVIDE ALL WATER, AND OTHER MATERIALS 3. THE FULL ROADWAY SECTION IS REQUIRED OVER THE SEEPAGE BED IN o �j\�j\ /\�j\�j��j\ (/\�j�� 4"SDR 35 PVC RISER N PAVED AREAS. // / 0. REQUIRED TO PERFORM THE TEST. THE PERCOLATION TEST SHALL BE �� �� �� �� �� �� �� \� s PERFORMED BY THE SOILS ENGINEER AFTER THE SEEPAGE BED IS 4. SEE STORM DRAIN PLANS FOR ADDITIONAL INFORMATION. I \>�\ �\��\��\��\ \��\� �/j x EXCAVATED TO VERIFY THE DESIGN INFILTRATION RATE. (NOTE: AN /\D/ /\D/\D/\D/ /\\/\D STORM DRAIN SERVICE 00 ACHD INSPECTOR MUST BE PRESENT TO WITNESS THE TEST FOR IT TO 5. THE BOTTOM ASTM C33 SAND ELEVATION IS THE MINIMUM EXCAVATION STORM DRAIN SERVICE I �j\�j\ /\D/\D/\D/\ /\D/\D �j\� p� BE CONSIDERED VALID). IF THE PERCOLATION IS LESS THAN THAT DEPTH. �D\\D SPECIFIED BY THE SOILS REPORT AND ENGINEER, CONTRACTOR SHALL 6. SEE ACHD STORMWATER DESIGN GUIDELINES BMP#20 "SEEPAGE BED" j\Oj Oj\Oj\Oj\Oj�Oj\Oj\ \Oj\ o Q� CONTACT ENGINEER TO RE-DESIGN THE SYSTEM TO ACHIEVE THE BUILDING LOT REQUIRED INFILTRATION. ACHD APPROVAL IS REQUIRED FOR ANY FOR ADDITIONAL REQUIREMENTS -"OPTIONAL CHAMBERS ARE NOT \\/\ \\/\\/\\/\ \\/\\/ \/\\/ MODIFICATIONS TO THE STAMPED, APPROVED DESIGN PLANS. REQUIRED. SIDE LOT LINE �I /�\/� /�\/�\/�\/� \/�\ \/�� O 10 7. GROUNDWATER WAS DETERMINED WITHIN THE PROJECT GEOTECHNICAL I X�AA��AA VA�VA�VA�VA�VA�VA� ��\j DRAIN ROCK SPECIFICATION GEOTEXTILE SPECIFICATION REPORT TO BE DEEPER THAN 2558, WHICH IS DEEPER THAN 20-FEET 5.00' 6"X4"SDR35PVCWY/ - FLOW // M BELOW THE GROUND SURFACE AS DETERMINED WITHIN THE PVC THREADED CAP GOETECHNICAL REPORT PREPARED BY ATLAS TECHNICAL CONSULTANTS \D\ D� � N Void Volume of T pical Materials Non-Woven Filter Fabric DATED 8/4/23. cIL �A D DA DA DAD DA \ D DA s 0 o Property Test Method English /o Material Void Volume Tensile Strength Grab ASTM D-4632 120 Ibs 8. THE DESIGN VOLUME OF THE FACILITY DOES NOT INCLUDE VOIDS WITHIN rG 2 th Max Blasted Rock 30 g (Grab) 4"SDR 35 PVC @ 2.0% 4"SDR 35 PVC WYE w3 � 1-'/2" to 2") Uniform Size Gravel 40 Elongation ASTM D-4632 50% THE ASTM C33 FILTER SAND LOCATED AT THE BOTTOM OF THE FACILITY. o W Uniform Size Crushed Chips 40 Puncture ASTM D-4833 65 Ibs p` 3UM Tra ezoidal Tear Stren th ASTM D-4533 50 Ibs 9• THE SEEPAGE BED WIDTH SHALL REMAIN CONSTANT ALONG THE o Crushed Glass 30 p g LONGITUDINAL LENGTH OF THE SEEPAGE BED. z U3 UV Resistance ASTM D-4355 70% PLAN VIEW SECTION VIEW A-A 06 Crushed aggregates shall have a minimum 50% crushed or fractured face (at Apparent Opening Size 10. IF ROCK IS ENCOUNTERED, CONTRACTOR MUST HAVE A PERCOLATION least on one side and meet the following gradation: (AOS) ASTM D-4751 70 US Std. Sieve TEST PERFORMED BY A SOILS ENGINEER AFTER SEEPAGE BED IS FULLY Permittivity ASTM D-4491 1.50 sec-1 EXCAVATED (NOTE: AN ACHD INSPECTOR MUST BE PRESENT TO WITNESS TomCrushed Aggregate Water Flow Rate ASTM D-4491 120 gpm/ft2 THE TEST FOR IT TO BE CONSIDERED VALID). IF THE PERCOLATION IS STORM DRAIN SERVICE 3 N z O LESS THAN THAT SPECIFIED BY THE SOILS REPORT AND ENGINEER, Sieve Size Percent Passing J w J M 0 o Woven Fabric CONTRACTOR MAY NEED TO BLAST OR BORE TO CREATE CONDUIT FOR 0 > � w 3 inch 100/o < 0 ,64 Y DRAINAGE TO OCCUR OR RE-DESIGN THE SYSTEM TO ACHIEVE THE SD.3 co CO 1 inch 25-60% Property Test Method English F < m o REQUIRED INFILTRATION. ACHD APPROVAL IS REQUIRED FOR ANY 2i - Y o -.- 3/8 inch 0-4% Tensile Strength (Grab) ASTM D-4632 Min 250 Ibs W MODIFICATIONS TO THE STAMPED APPROVED DESIGN PLANS. W Q " N X z No. 200 0-2% Puncture Strength or CBR ASTM D-4833 or Min 125 Ibs or Min 950 o _ < � N Puncture ASTM D-6241 Ibs 11. FOR UNDERGROUND INFILTRATION SYSTEMS, INSTALL ELECTRONIC ' a 0- w o LL o UV Resistance ASTM D-4355 Min 80% MARKERS ON EACH CORNER OF THE FACILITY. THE CONTRACTOR SHALL Z N Apparent Opening Size COORDINATE WITH THE ACHD INSPECTION DEPARTMENT FOR PLACEMENT JOB NUMBER: M� (AOS) ASTM D-4751 70 US Std. Sieve OF THE MARKERS DURING CONSTRUCTION, AND PRIOR TO BACKFILLING. OHO R IDB2355 �++ Water Flow Rate ASTM D-4491 Min 18 gpm/ft PRIVATE SEEPAGE BEDS DO NOT REQUIRE ELECTRONIC MARKERS. �OJ G��O� Q DATE: 8-21-23 Percent Open Area CW-02215 Min 4% Q O� AQ G`Q � SHEET NUMBER: SEEPAGE BED CROSS SECTION Go J SD.3 J 1 B 2 5 LEGEND 7 - - - - - - - - - - - - - - - - - - - - - - � 36" O1 TROWEL SMOOTH I I 28" 6 O EDGE OF GUTTER I I 1 1 O3 1.75" X 1.75" X 1/4" ANGLE IRON. I STANDARD GRATE FRAME A N A SEE SD-609 AND SD-610A A -a F A ---------------- --T F-- ---------------- NOTCH O4 PAVEMENT SURFACE. I O� O� I 2 X2 A A O5 STANDARD GRATE AND GRATE FRAME. SEE I �CO� ���� SD-609 OR SD-610A. --- 2 © 4" X 4" X 3/8" ANGLE IRON I I (3) 7" NO.4 BARS 2 1/16" LIP (TYPICAL) I - `� N N TOP VIEW ,� 2a' L - - - - - - - - - - - - - - - - - - - - - - � 4„ \ 4" N 4" 18" 6" R1 2" d 3 4" / / PLAN VIEW s E ti 1 3 I TYP. Q 6 1/2" 6 1 N.T.S. 6 O - _ 3 L:i a.. V a -gz� - o 5 oo y +i+ �a3 yy 111=III=III=III=1 1=11 Q �, o a SECTION B-B SECTION A-A ISOMETRIC II-III=III-III-II 3 _ 1-III=III-III-III= 3 -ICI-ICI-ICI-ICI ICI-ICI-ICI-III-I p Er_ y o N.T.S. B p jffR III-1 I=1 I-I -I :' _ -1 I-III-III I- e o 5 B -III-III-III I I= -1 1 I-V Q B GRATE TYPE III TI-1T1=�T —ICI-1T1- a B —1 1= 5 0.20% MIN SLOPE 7 a Q +' o 2 a z TOP VIEW -- II--- � N N a92 N.T.S. I I 3 2 I H 4 I "w d Tom m I nn II'' BAFFLE WALL 8" RADIUS UP TO INLET CATCH 4 I�V� 4 OUTLET d BASIN, SEE ROLLED CURB SD-702. 6„ 18" 4" 3 Q� o FLOW- HAND ELEV B HAND FORM RADIUS AT FLOW ' INLET CATCH BASIN TO FIT I 2" 28 4" 3 PLAN ELEV A 51/2" 4 ELEV D ' N.T.S. s" 1'-2" 8" INLET BAFFLE WALL 4 p ELEV C z 2" LIP °- - 4 - 20" STD 2" 6 SEE NOTES BELOW 3-0 2-4 M s" 2'-0" s" roP of cuRB CONTACT DMINE Ld� .. 2„ 7 � 27 1/2" I.D. SECTION A—A 48—HOURg a 0.OPEN FLOWLINE OF CURB N.T.S. SECTION A-A gEF01 DIGGING LEGEND N.T.S. BASE OF CURB �-SOO'34Z-1.�S5 Oj ADJOINING TOP OF CURB. NOTCH 4. NOTES O OUTLET. CATCH 1-3/4" x 1-3/4" x 1/4" 2 x2 II—III— 1. SAND AND GREASE TRAP USED FOR SUBSURFACE FACILITIES ONLY AREA STEEL ANGLE —I�I— O3 PAVEMENT SURFACE. 2 28 LEGEND: 4 STANDARD GRATE AND GRATE FRAME, TOP VIEW END VIEW -III—I 1 MANHOLE FRAME AND COVER PER SD-617 (TYPICAL) N 111=III w z LOCATION AND FL ELEV. PER DESIGN PLANS (TYPICAL) O SEE SD-609 OR SD-610A. —III-- U Cn O STANDARD ROLLED CURB AND GUTTER. 8 1 -2 6 - I—I J = 3 H 1-FT USE GRADE RINGS TYPICAL J Q GRATE FRAME DETAIL —1 11= 1—FT < H <= 2—FT USE 24" DIA RCP RISER a ©4" X 4" X 3/8" ANGLE IRON NOTES -I I I—I I 2'-4" N.T.S. I 2-FT < H <= 10-FT USE MANHOLE CONE & 48" DIA RISERS CV O7 (3) 7" N0.4 BARS D FOUR-SIDED FRAME IS REQUIRED. —1 1I— -I�I-�I (DEL. A > EL. B BY 0.10' MIN w O p LEGEND -I 11- EL. D < EL. B BY 0.10' MIN U) Z ®EDGE OF GUTTER SECTION A—A =III—I EL. C < EL. B BY 0.50' MIN. UNLESS OTHERWISE APPROVED BY ACHD Q O1 1-1/2" x 3/4" STEEL BARS (TYP.). Q N.T.s. ,I—I�I- 5 WATERTIGHT SEAL 2 O2 1/4" FILLET WELD ALL BARS. -1 I1= 8 PRECAST BOX MANUFACTURER SHALL MARK FLOW DIRECTION AND LABEL INLET OR OUTLET 0 4 PLACES (TYP.) SECTION B—B ON SIDE OF BOX Q CO O Lu WELD (4) 1/2"x7" STUDS. N.T.S. 0 2017 ACHD REVISION 2017 ACHD REVISION Q < 2017 ACHD REVISION 2015 SAND AND GREASE TRAP STANDARD DRAWING IDAHO STANDARDS STANDARD DRAWING IDAHO STANDARDS STANDARD DRAWING IDAHO STANDARDS STANDARD DRAWING ACHD STORMWATER DESIGN Q INLET CATCH BASIN CATCH BASIN GRATE INLET CATCH BASIN GUIDELINES BMP 01 QLIJ FOR PUBLIC WORKS NO- FOR PUBLIC WORKS NO. FOR PUBLIC WORKS NO. 1 OF 2 07 _ Q CONSTRUCTION TYPE IV (FOR ROLLED CURB) SD- 604A CONSTRUCTION TYPE III SD- 610A CONSTRUCTION TYPE SD- 601 (ACHD SUPPLEMENT) (ACHD SUPPLEMENT) (ACHD SUPPLEMENT) U w w z 0_ O d 1 LEGEND ANAL Qi WELL COVER, 8" DIA. WATERTIGHT GALVANIZED STEEL BOLT DOWN COVER AND CANISTER 2 2 OR 3 BOLT LID WITH 9/16" HEAD AND SAE THREADS, GASKETED y p�c� <cG\STE F /"CO FINISH GRADE O CONCRETE (COLLAR), CLASS 3000 (ISPWC SECTION 703) / Q� 1 z O4 3/8" DIA HOLES OR SLOTS CUT INTO PIPE AT 3" ON CENTER Q O TRACER WIRE SHALL BE PLACED ON OUTSIDE OF PVC PIPE, MINIMUM 18 GAUGE, INSULATED, SINGLE- / O 00000 0 \ EXTEND PIPE (1" TO 6" MAX.) 3 CONDUCTOR COPPER WIRE, INSULATION COLOR SHALL BE GREEN WITH THREE 6" DIAMETER COILS ./ ❑O O O O O ❑O ` I INSIDE MANHOLE ° - - - Q. OOOOOOO I-III 11=III=III _ _ _ 0 PIPE SHALL BE PERFORATED PVC, ASTM D-3035, SDR 35. WELLS BACKFILLED IN A PIT REQUIRE 6" O O O O O O 7 �'� 8-21-23 O O 9T �QP., -III III-III III-��II11111=11 °�'b: °,'Q. PIPE. DRILLED WELLS MAY USE 4" PIPE O O STORM O I A III=III-II -III- Q,. 0' NONWOVEN FILTER FABRIC AROUND OPENINGS AND BOTTOM, FABRIC OVER CHIPS/DRAIN ROCK 00 DRAIN 00 - SS K III—III III=III 1=III=11 III=III= - . Q - POLYPROPYLENE FIBER REINFORCEMENT AT 1 1 2 LBS CY - 111—III ao ":',>,�,',.. AP `.=>.p-•> / / Q O BACKFILL MATERIAL TO MATCH STORAGE MEDIA FOR OBSERVATION WELLS LOCATED WITHIN A BMP FACILITY. °� 0�00000000000 11 LEGEND a USE PIPE BEDDING CHIPS FOR OBSERVATION WELLS LOCATED OUTSIDE BMP FACILITIES \ O O O O O ' ' _ • c\I • LO PIPE FROM INLETS • • • O1 CONCRETE COLLAR IN PAVED STREET SECTIONS .• .• • \3 3 AND/OR TEE IN PER SD-616. , 00 • • 3 NOTES: MAIN LINE. • • . • 5 I 2 GRADE RINGS GROUTED WATERTIGHT IN PLACE, 0 0 0 PLAN CONCRETE COLLAR 1. GROUNDWATER OBSERVATION WELLS ARE FOR MEASUREMENT OF GROUNDWATER LEVELS WITHIN OR NEAR • I O NOT TO EXCEED 18" FROM FINISHED SURFACE � 0c 0c • STORM DRAINAGE FACILITIES I • • • N.T.S. 2. THIS DETAIL IS FOR WELLS INSTALLED BY DRILLING OR BY EXCAVATED PITS I I TO TOP OF CONE. , c-5 3. LOCATION OF GROUNDWATER OBSERVATION WELLS SHALL BE APPROVED BY ACHD O PRECAST MONOLITHIC ECCENTRIC CONE SECTION. • Q (REBAR NOT SHOWN). �� 4. OBSERVATION WELLS NOT ALLOWED IN CURB OR VALLEY GUTTER SECTION 4 N P LAN O RAMNEK OR APPROVED GASKETS AT ALL JOINTS. • 0 w PLAN N.T.S. O5 PROPERLY ALIGN ALL INTERIOR JOINTS. p > 18 1 -O„ 6 N.T.S. © PRECAST CONCRETE MANHOLE BARREL SECTION m (MIN.) (REBAR NOT SHOWN). O 7 O PRECAST GASKETED HUB RING OR RUBBER LLI m 1 0 a °,o °, e °,< 6 10 9 8 GASKETED COLLAR. F F o OlDf I => ® SURFACING TO MATCH FLUSH WITH EXISTING SURFACING (AS SHOWN). Qo a W 24" DIA. O9 FRAME TO BE GROUTED TO GRADE RINGS. <z O (n e ' Q Q 1 10 FRAME AND COVER PER SD-617. z. N w 6 SECTION CONCRETE COLLAR Zol Q `a 8 4" (MIN) 11 MANHOLE STEPS. NU > N.T.S. °° `° 2 �m 8' SEE SD-501 FOR CAST IN PLACE MANHOLE N BASE. SEE SD-501A FOR PREFABRICATED oN ° ° 4 2'-0" 3 BASE. zQ w OR 2'-6" NOTES: LL cd 9 4 OA OPTIONAL PREFABRICATED MANHOLE BASE WITH og NOTE: v 5 ENGINEEAPPROVERS APPROVAL,PE SEEDM501.AY USED WITH ZO wz SECTION A—A _ 9 A TOP OF COLLAR TO BE FLUSH O © PLACE VERTICAL WALL ON UPSTREAM SIDE OF dz > ON.T.S. WITH MANHOLE COVER. 6 11 6 MANHOLE, ROTATED 45 DEGREES. > w� © of 3LB PER CY OF FIBER-REINFORCED 48" © FOR INLET PIPE DIAMETER, D, GREATER THAN 24", z O ° ° CONCRETE MAY BE USED IN LIEU OF z ` SEE SD-613 OR SD-614. �N , ° ° LEGEND REBAR WITH ENGINEER'S APPROVAL. a O1 4 REBAR 2 EACH SEE SECTION A-A . OD MANHOLE FRAME AND COVER: Jw o o N # ( ) ) 6" (MIN) A. REFER TO DRAWING NO. SD-617. ao B FRAME AN COVER SHALL BE FLUSH WITH ° O #4 REBAR AT 20" SPACING. 7 r: ' SLOPE OFDPAVEMENT.A L -0 12 C. "STORM DRAIN" ON COVER. 3 SCORES. 1/8 1/4 i ,:' ,` J O ' E : `', O WHERE PVC PIPE IS UTILIZED, INSTALL A RUBBER zz w �--►� 04 RIM. RING OR GASKET COLLAR WHERE THE PIPE IS IN rK 10 CONTACT WITH MANHOLE BASE AND/OR MANHOLE w3 SECTION O FRAME AND COVER PER SD-617. SECTION A—A CHANNEL, IN ORDER TO INSURE A WATERTIGHT 4" TYPE 1 N.T.S. SEAL. o © SEE "DETAIL A" FOR REBAR IN COLLAR. BEDDING �3 �+ 6" F EITHER BASE ON SD-501 OR SO-501A MAY BE iY N.T.S. O7 um FINISHED GRADE. / O USED WITH EITHER MANHOLE DESIGN. a� 2" (MIN.) ° . z o3 ® SEE OTHER STANDARD DRAWINGS OF MANHOLES FOR MAXIMUM HEIGHT. O9 GROUT BETWEEN RING AND COVER AND GRADE RINGS. 1O FRIBILLATED TUDSEDONYPROUYLENE FIRER (1 IN 2 LBS.TEPER CY) DETAIL A N COLLARS. N.T.S. 2017 ACHD REVISION 2017 ACHD REVISION J O 2017 ACHD REVISION z � 2017 ACHD REVISION IDAHO STANDARDS - IDAHO STANDARDS IDAHO STANDARDS FOR PUBLIC WORKS STANDARD CONCRETE NO NDARD DRAWING Q z m z � 0 FOR PUBLIC WORKS GROUNDWATER STANDARD DRAWING FOR PUBLIC WORKS GROUNDWATER STANDARD DRAWING IDAHO STANDARDS STANDARD DRAWING CONSTRUCTION OBSERVATION WELL SD - 627 OBSERVATION WELL SD- 627 FOR PUBLIC WORKS MANHOLE COLLAR N0. _ (ACHD SUPPLEMENT) CATCH MANHOLE SD- 611 0 w a _ N CONSTRUCTION CONSTRUCTION w a - " (ACHD SUPPLEMENT) (ACHD SUPPLEMENT) CONSTRUCTION S D 61 6 0 w W IL U Q 1 OF 2 2 OF 2 ACHD SUPPLEMENT a a o O z N O 5 JOB NUMBER: IDB2355 m O"�O�O� 0 DATE: 8-21-23 AQe�V� � SHEET NUMBER: �O OAS SDm4 yo W ENCLOSE TOP & SIDES OF ROCK WITH NON WOVEN GEOTEXTILE FABRIC SAND/GREASE TRAP (ISPWC SD-624) OR s 1/2" 2'-6" SEDIMENT MANHOLE (ISPWC SD-61 1) 1-FT MIN TYP 6" MIN TYP 18" DIA. HDPE OR PVC 1/16" CLEARANCE 18" DIA. CORRUGATED HDPE IF INSTALLED WITH CHAMBERS/ PERFORATED PER 2' RING & OR PVC PIPE PERFORATED PER CHIPS, INSTALL WOVEN ENCLOSE TOP & SIDES OF ROCK SCHEDULE BELOW A COVER PER WITH NON WOVEN FILTER FABRIC SEE COVER PERFORATION SCHEDULE GEOTEXTILE TO SEPARATE CHIPS OBSERVATION WELL #1 A 00 ISPWC SD-617 AND DRAIN ROCK �ON OPPOSITE SIDE OF STREET IN SIDEWALK OR a (TYP) TREES & SHRUBS NOTES ARE NOT PERMITTED MIN 50' DISTANCE o OBSERVATION OPTIONAL STORMWATER STORAGE "-2" CHIPs;ON TOP OF SEEPAGE WELL CHAMBERS, SHAPE & SIZE —� CO eWQ o w BED VARY PER MANUFACTURER �c 3 a 1 �On >X,,c 18" �d O ELEV BOTTOM PERF <= EE COVER ` ///\ / ° 12" 4 \�\\/ \�\\ WOVEN GEOTEXTILE BETWEEN o ELEV BOTTOM BAFFLE NOTES /\/\/\\j\\//\i 57 3/4" CHIPS AND 2" DRAIN ROCK L —12" DIA. HDPE , O C 0 0 0 0 0 0 0 0 0 0 o 0 0 0 0 /\j\\%\\\/\%\%\ OVERLAP WOVEN AND NON aa� V w OR PVC SD PIPE PLAN L U U SEE 5 0 0 0 0 0 0 18 0 0 0 0 0 0 0 0 \\j\\/ \ /\\j\\ WOVEN GEOTEXTILE A MIN OF I = PERFORATED ® ® —� ® �— ® N.T.S. 6 O v N a o -- -- -- -- cn cn O O C y o NOTE 11 STD SLOPE \ \jNATIVE\\ \\ 1-FT ON ALL SIDES 2" WASHED DRAIN w 2" WASHED DRAIN L PER SCHEDULE 7 )OU O�C - / 0% SLOPE 0% s .o ROCK OR CHIPS> ROCK OR CHIPS> ; NOTEW1 1 SEE Ooo a0 g o s E y . . LL /\\j\\%NATIVE \\�j\\\\\\ 2" WASHED VARIES-SEE 2„ WASHED ewa \ 3/4„ 9„ OQC W Z L E as u o OoO° En ` \ DRAIN ROCK PLAN SHEETS DRAIN ROCK /\/\\j\\%j\\ "' ' O MAINTENANCE _Q \\ \/• //\i \\ �- \\ \j \ 1.5-FT 1.5-FT DIVERSION STRUCTURE WITH ACCESS TO °Oy Oo°O _ RAISED INVERT OR WEIR WALL STRUCTURES - o°O Oo°O°O° v 5' OF 18" SOLID . . Joo' OoO Oo°ODOo° on Q ow ASTM C33 ASTM C33 ASTM C33 oJ0 Oo00o00oO0oO0oO0oO Oo00o00000000o00d C 1 .. .....::: WALL PIPE WITH 1.5-FT DTH VARIES 41 -� �_ ` FILTER SAND.::;.:.1' `FILTER SAND;':: , ,'.:, FILTER HIGH FLOW BYPASS PIPE WQ PIPE, +. 4» OF 4" PIPE BEDDING ':; 3-� 15' MAX WIDTH 1 1 ON BMP 20 PERF TOP HALF 8„ Q N o WI S PER PLAN SAND SEE NOTE �H w MAX HSGW (1 of 3) w 10 NONWOVEN FILTER FABRIC. OVERLAP TRANSITION 5-FT IN o O O O O Oo O O O O O O O O C ca • w MINIMUM OF 1-FT TOP AND BED NON-PERFORATED -ELEVATION OPTIONAL CHAMBER STANDARD 21 °O°O°O°O°O °O °O°O°O°O°O O °O°C IL rw aTo d ,� m m SIDES ONLY TO PERFORATED PIPE SECTION SECTION SECTION A-A N.T.S. N.T.S. Li SECTION A—A 8 N.T.S. CAST IRON `\ ^ NOTES: OBSERVATION � B•� 10 s ' 1. BMP 1-4 OR VEGETATED PRETREATMENT IS REQUIRED. I� WIDTH PLAN-SEEPAGE BED RING & COVER 2. CONTACT DESIGN PROFESSIONAL FOR SEEPAGE BED REDESIGN IF GROUNDWATER IS ENCOUNTERED ABOVE WELL #1 r \ �c� I 4S• / I OUTSIDE ROADWAY S ED N.T.S. MAX HSGW ELEVATION 3. ALL VAULTS, MANHOLES, & SAND AND GREASE TRAPS SHALL BE HS25 OR GREATER LOAD RATED N.T.S. SIDE 4. SEEPAGE BED SHALL BE SHOWN ON BOTH PLAN AND PROFILE VIEWS n OBSERVATION WELL #1 5. OPTIONAL CHAMBERS PER MANUFACTURERS SPECIFICATIONS >T ON OPPOSITE SIDE OF STREET IN SIDEWALK OR N.T.S. 6. ALL GEOTEXTILE SEAMS SHALL OVERLAP 1 FOOT MINIMUM CONTACT DMINE 7. EL. IN >= EL. BOTTOM PERFORATIONS IN 18" PERF PIPE �4S•I h5 Sidewalk 48-HOURS 8. MAXIMUM BED LENGTH IS 400-FT BETWEEN MANHOLES A A 18" PERF PIPE 12" PERF PIPE LEGEND BEFORE DIGGING 9. BED WIDTH SHALL REMAIN CONSTANT = WQ BYPASS SEE NOTE 11 12" 4" 12" 1-800-342-IN5 10. WATERTIGHT CONNECTION REQUIRED CD (D 4- 1" DIA. HOLES ON 3 1/2" RADIUS. 11. HIGH FLOW BYPASS PIPE ONLY NEEDED IF Q100 VELOCITY THROUGH STRUCTURE > 0.5 FPS z1 OBSERVATION PERFORATION SCHEDULE - WELL #2 3/8" PERFORATIONS IN VALLEYS SD PIPE O2 MECHANICAL PLUG. ® ® HI F BYP-7 PIPE ® E ® , COVER NOTES: ACROSS STREET OF CORRUGATED PIPE. 5 EA ON SE NOTE 11 ON M 12" DIA. X 1'-0" PVC, DIP OR CP. FOR SEEPAGE BEDS OUTSIDE PUBLIC RIGHT-OF-WAY: WITHIN SIDEWALK 18", 8 EA ON 12" 1. A MINIMUM 1.5-FT COVER FROM TOP OF BED TO FINISH GRADE IS REQUIRED (1 of 3) Io 0 o Oo0 (n� (On�o° ® FIBER JOINT MATERIAL. N !SEEHAGE BED 1000 O �0 00 00 11 O PVC ASTM D 3034. (� FOR SEEPAGE BEDS IN PUBLIC RIGHT-OF-WAY: Q 1. A MINIMUM 1.0-FT COVER FROM TOP OF BED TO PAVEMENT SUBGRADE IS REQUIRED Sidewalk PPR�B1=21P� ® non° o- - �O°�O�O © 45' BENDS. J = --BACKFILL OVER BED TO SUBGRADE WITH 6"-8" MINUS PITRUN i 1 '� d Od Od Oo00o0000, a --WOVEN GEOTEXTILE FABRIC REQUIRED OVER TOP OF BED A 0 "Y" FITTINGS. CV --TOP OF BED UNDER SIDEWALK SHALL BE MIN 1.0-FT BELOW PAVEMENT SUBGRADE PLAN 8 EXISTING OR NEW PIPE. LLI Z OBSERVATION WELLS: 2 REQUIRED PER BED O O_ � 2. IF < 1.0-FT COVER FROM TOP OF BED TO SUBGRADE, ANGULAR 4" TO 2" ROCK IS REQUIRED WITH N.T.S. WQ PIPE, DIVERSION STRUCTURE WITH s TYPE 1 BEDDING MATERIAL. Q z MINIMUM 50% SINGLE FRACTURED FACE IN PLACE OF 2" DRAIN ROCK. PERF TOP HALF RAISED INV OR WEIR WALL = Q 3. FULL ROADWAY SECTION IS REQUIRED OVER SEEPAGE BEDS. SEEPAGE BEDS SHALL NOT EXTEND ABOVE 10 MISSION COUPLER OR APPROVED SUBSTITUTION. REQUIREMENTS FOR FACILITIES IN RIGHT-OF-WAY 0 cl SUBGRADE PLAN-SEEPAGE BED SECTION B—B 11 UNDISTURBED MATERIAL. CO � 4. THE DESIGN PROFESSIONAL IS SOLELY RESPONSIBLE FOR ASSESSING THE BEARING RESISTANCE OF THE 1. BED IS LIMITED TO AREA WITHIN 5-FT OF CURB FACE UNDER ROADWAY; UNDER SIDEWALK N.T.S. < Z) w SUBGRADE SOILS AND DETERMINING THE DEPTH OF FOUNDATION STONE 2. NO GREATER THAN 10-FEET IN DEPTH TO THE BOTTOM OF THE ROCK; ct) 2i SEE BMP 20 SHEET 2 OF 3 FOR ADDITIONAL NOTES 3. MAY NOT EXTEND OUTSIDE OF THE RIGHT-OF-WAY (MAY NOT ENCROACH ON PRIVATE LOT IN AN EASEMENT); N.T.S. ui co Q Q 2015 Q 2017 SEEPAGE BED WITH STANDARD DRAWING 2017 SEEPAGE BED WITH STANDARD DRAWING 2017 SEEPAGE BED WITH STANDARD DRAWING » ~ ACHD STORMWATER DESIGN ACHD STORMWATER DESIGN ACHD STORMWATER DESIGN IDAHO STANDARDS STANDARD 4 TRAFFIC STANDARD DRAWING w w GUIDELINES OPTIONAL CHAMBERS BMP 20 GUIDELINES OPTIONAL CHAMBERS BMP 20 GUIDELINES OPTIONAL_ CHAMBERS BMP 20 FOR PUBLIC WORKS No. o a SHEET 1 OF 3 SHEET 2 OF 3 SHEET 3 OF 3 CONSTRUCTION RATED CLEAN —OUT SD- 506A �SS\0AL ENG� G\STE 3 8-21-23 �o 0 ER . . . • .• .• 24"DIA.CAST IRON RING • • • • • • 24"DIA.CAST IRON RING AND SLOTTED COVER(TYP.) , '• '• '• AND SLOTTED COVER(TYP.) • • � � � • 4'-0" ' • 1 2'-5" V-6" �� 5„ CL r CL 6 TOP OF BOX co 3 • N O W `n A A GROUT PIPE 11 0 ~� PERFORATIONS OUTLET + I C4 ¢o TO STRUCTURE 0 z o. N U 3'-42' 3'_82" �— 1 + I — �a3 4'-0" ID �G14 OUTLET BAFFLE z 3„ �N 00 o N o 3 1' 111" 0 0g I I CL2 1' 84" Z w� rl/ �I m w z W 0 L — — w> K U O - - - _ - F O 4" Y 1 FLOOR 3' 5" 3'-5" aLL M ID ID o O 3'-11" 11" zm 3' PLAN VIEW O zz PROFILE VIEW SECTION A - A o3 N wo 3 ILo ro. LLI o3AMCOR DB-350 CATCH BASIN 1 SD.5 M O JLID W a � � 00 11 00 a Z OW I-_ N m 0MN1 Z o 0 LU WILI O z N JOB NUMBER: 1 O O0 IDB2355 m �O,o, 0 DATE: 8-21-23 AQe�Vv � SHEET NUMBER: SDm 5 I NJ 1 W � Q W "A- MOM46 * vw _ � :l• �j� 4r�� 4 e. - r r GEOTECHNICAL INVESTIGATION - REVISED SAGARRA SUBDIVISION 913 & 1241 W Orchard Park Dr Meridian, ID PREPARED FOR: Brock Adley Lincoln Property Company 176 S Capital Boulevard Boise, ID 83702 PREPARED BY: Atlas Technical Consultants, LLC 2791 South Victory View Way August 4, 2023 Boise, ID 83709 B231179g MOM 0 �r'N-r-�-A�1 2791 South Victory View Way Boise, ID 83709 (208)376-4748 i oneatlas.com August 4, 2023 Atlas No. B231179g Brock Adley Lincoln Property Company 176 S Capital Boulevard Boise, ID 83702 Subject: Geotechnical Investigation - Revised Sagarra Subdivision 913 & 1241 W Orchard Park Dr Meridian, ID Dear Brock Adley: In compliance with your instructions, Atlas has conducted a soils exploration and foundation evaluation for the above referenced development. Fieldwork for this investigation was conducted on July 17, 2023. Data have been analyzed to evaluate pertinent geotechnical conditions. Results of this investigation, together with our recommendations, are to be found in the following report. We have provided a PDF copy for your review and distribution. Revisions in this report include modifications to the Groundwater section. Often, questions arise concerning soil conditions because of design and construction details that occur on a project. Atlas would be pleased to continue our role as geotechnical engineers during project implementation. If you have any questions, please call us at (208) 376-4748. Respectfully submitted, G"I- ku" Colby Meyer, GIT Monica Saculles, PE Staff Geologist Senior Geotechnical Engineer Clinton Wyllie, PG Staff Geologist Page 1 �TrT-G7T-�. CONTENTS 1. INTRODUCTION................................................................................................................. 2 1.1 Project Description ..................................................................................................... 2 1.2 Scope of Investigation................................................................................................ 2 2. SITE DESCRIPTION........................................................................................................... 3 2.1 Regional Geology....................................................................................................... 3 2.2 General Site Characteristics....................................................................................... 3 3. SEISMIC SITE EVALUATION ............................................................................................ 3 3.1 Geoseismic Setting .................................................................................................... 3 3.2 Seismic Design Parameter Values ............................................................................. 4 4. SOILS EXPLORATION....................................................................................................... 4 4.1 Exploration and Sampling Procedures........................................................................ 4 4.2 Laboratory Testing Program....................................................................................... 5 4.3 Soil and Sediment Profile........................................................................................... 5 4.4 Volatile Organic Scan................................................................................................. 5 5. SITE HYDROLOGY... ................................................................................................. 6 5.1 Groundwater.............................................................................................................. 6 5.2 Soil Infiltration Rates .................................................................................................. 6 6. LATERAL EARTH PRESSURES ....................................................................................... 7 6.1 Retaining Wall Backfill Materials................................................................................. 8 6.2 Retaining Wall Drainage............................................................................................. 9 7. FOUNDATION AND SLAB DISCUSSION AND RECOMMENDATIONS............................ 9 7.1 Foundation Loading Information................................................................................. 9 7.2 Foundation Design Recommendations....................................................................... 9 7.3 Floor Slab-on-Grade..................................................................................................11 8. CONSTRUCTION CONSIDERATIONS .............................................................................11 8.1 Earthwork..................................................................................................................11 8.2 Grading .....................................................................................................................12 8.3 Dry Weather..............................................................................................................12 8.4 Wet Weather.............................................................................................................12 8.5 Soft Subgrade Soils...................................................................................................12 8.6 Frozen Subgrade Soils..............................................................................................13 8.7 Structural Fill .............................................................................................................14 8.8 Fill Placement and Compaction.................................................................................14 8.9 Backfill of Walls.........................................................................................................16 8.10 Excavations.............................................................................................................16 8.11 Groundwater Control...............................................................................................17 9. GENERAL COMMENTS....................................................................................................17 Atlas No. B231179g Page I i Copyright©2023 Atlas Technical Consultants 10. REFERENCES.................................................................................................................18 TABLES Table 1 — Seismic Design Values................................................................................................4 Table 2 —Typical Soil Profiles.....................................................................................................5 Table 3 — Groundwater Data.......................................................................................................6 Table 4 — Generalized Soil Infiltration Rates ...............................................................................7 Table 5 — Lateral Earth Pressure Values.....................................................................................8 Table 6 — Soil Bearing Capacity................................................................................................10 Table 7 — Fill Material Criteria ...................................................................................................14 Table 8 — Fill Placement and Compaction Requirements..........................................................14 APPENDICES Appendix I Warranty and Limiting Conditions Appendix II Vicinity Map Appendix III Site Map Appendix IV Geotechnical Investigation Test Pit Log Appendix V Geotechnical General Notes Appendix VI Important Information About This Geotechnical Engineering Report Atlas No. B231179g Page I ii Copyright©2023 Atlas Technical Consultants 1. INTRODUCTION This report presents results of a geotechnical investigation and analysis in support of data utilized in design of structures as defined in the 2018 International Building Code (IBC). Information in support of groundwater and stormwater issues pertinent to the practice of Civil Engineering is included. Observations and recommendations relevant to the earthwork phase of the project are also presented. Revisions in plans or drawings for the proposed development from those enumerated in this report should be brought to the attention of the soils engineer to determine whether changes in the provided recommendations are required. Deviations from noted subsurface conditions, if encountered during construction, should also be brought to the attention of the soils engineer. 1.1 Project Description The proposed development is in the City of Meridian, Ada County, ID, and occupies a portion of the N'/2NW'/4 of Section 25, Township 4 North, Range 1 West, Boise Meridian. The site to be developed is approximately 15.43 acres. Site maps included in the Appendix show the project location. This project is expected to consist of a residential development comprised of single-family residential structures, townhome/cottage structures, and 2-story apartment structures. A community pool and retaining walls may be constructed as part of the project. Residential roadways will be developed for the project. Drainage is expected to be directed to onsite infiltration facilities. Location of the infiltration facilities are unknown at this time. 1.2 Scope of Investigation Our scope of work was completed in general accordance with our proposal dated June 19, 2023 and authorized on July 28, 2023. Said authorization is subject to terms, conditions, and limitations described in the Professional Services Contract entered into between Lincoln Property Company and Atlas. Atlas' scope of services included the following: • Subsurface exploration via test pits. • Field and laboratory testing of materials encountered and collected. • Preparation of this report, which includes project description, site conditions, and our engineering analysis and evaluation for the project. Atlas No. B231179g Page12 Copyright©2023 Atlas Technical Consultants 2. SITE DESCRIPTION 2.1 Regional Geology The project site is located within the western Snake River Plain of southwestern Idaho and eastern Oregon. The plain is a northwest trending rift basin, about 45 miles wide and 200 miles long, that developed about 14 million years ago (Ma) and has since been occupied sporadically by large inland lakes. Geologic materials found within and along the plain's margins reflect volcanic and fluvial/lacustrine sedimentary processes that have led to an accumulation of approximately 1 to 2 km of interbedded volcanic and sedimentary deposits within the plain. Along the margins of the plain, streams that drained the highlands to the north and south provided coarse to fine-grained sediments eroded from granitic and volcanic rocks, respectively. About 2 million years ago the last of the lakes was drained and since that time fluvial erosion and deposition has dominated the evolution of the landscape. The project site is underlain by the "Gravel of Whitney Terrace" as mapped by Othberg and Stanford (1993). Sediments of the Whitney terrace consist of sandy pebble and cobble gravel. The Whitney terrace is the second terrace above modern Boise River floodplain, is thickest toward its eastern extent, and is mantled with 2-6 feet of loess. 2.2 General Site Characteristics The following details regarding site conditions are based on visual observations and review of available geologic and topographic maps and imagery: • Current Site Conditions: The site is approximately 15.43 acres and consists of undeveloped land. Orchard Park Drive meanders roughly east to west along the northern edge of the site. Bergman Avenue Runs north to south bisecting the central portion of the site. Landscaping and sidewalks are in place along the existing roadways adjacent to the site. Residential developments are present to the south and east of the site, while commercial properties exist to the north and west. • Vegetation: Vegetation on the site consists primarily of native brush and weeds. Landscape grasses and trees are present along the roadways in the northern and central portions of the site. • Topography: The site is relatively flat and level. • Drainage: Stormwater drainage for the site is achieved by percolation through surficial soils. The site is situated so that it is unlikely that it will receive any drainage from off-site sources. 3. SEISMIC SITE EVALUATION 3.1 Geoseismic Setting Soils on site are classed as Site Class D in accordance with Chapter 20 of the American Society of Civil Engineers (ASCE) publication ASCE/SEI 7-16. Structures constructed on this site should be designed per IBC requirements for such a seismic classification. Our investigation revealed low hazard potential resulting from potential earthquake motions including: slope instability, liquefaction, and surface rupture caused by faulting or lateral spreading. Atlas No. B231179g Page 13 Copyright©2023 Atlas Technical Consultants 3.2 Seismic Design Parameter Values The ASCE 7-16 seismic design parameter values have been provided below. Table 1 — Seismic Design Values Seismic Design Parameter Design Value Site Class D "Default" Site Modified Peak Ground 0.201 Acceleration, PGAM Ss 0.295 (g) S1 0.107 (g) Fa 1.564 Fv 2.385 Sens 0.462 SM1 0.256 Sys 0.308 Sol 0.171 4. SOILS EXPLORATION 4.1 Exploration and Sampling Procedures Field exploration conducted to determine engineering characteristics of subsurface materials included a reconnaissance of the project site and investigation by test pit. Test pit sites were located in the field by means of a Global Positioning System (GPS) device and are reportedly accurate to within ten feet. Upon completion of investigation, each test pit was backfilled with loose excavated materials. Re-excavation and compaction of these test pit areas are required prior to construction. Samples obtained have been visually classified in the field, identified according to test pit number and depth, placed in sealed containers, and transported to our laboratory for additional testing. Subsurface materials have been described in detail on logs provided in the Appendix. Results of field and laboratory tests are also presented in the Appendix. Atlas recommends that these logs not be used to estimate fill material quantities. Atlas No. B231179g Page14 Copyright©2023 Atlas Technical Consultants 4.2 Laboratory Testing Program Along with our field investigation, a supplemental laboratory testing program was conducted to determine additional pertinent engineering characteristics of subsurface materials. Laboratory tests were conducted in accordance with current specifications. The laboratory testing program for this report included: Atterberg Limits Testing —ASTM D4318 Grain Size Analysis —ASTM C117/C136 Resistance Value (R-value) and Expansion Pressure of Compacted Soils — Idaho T-8 As to date, the R-value test results have not been received and, therefore, have not been included within this report. Atlas will forward the results in the form of an addendum once the R-value test results have been received. r.s Soil and Sediment Profile The profile below represents a generalized interpretation for the project site. Note that on site soils strata, encountered between test pit locations, may vary from the individual soil profiles presented in the logs. Table 2 —Typical Soil Profiles Soil Horizons Approxi Consistency7et.. Dept s Density Fill Materials' 0 to 1.5 feet Clayey Gravel with Sand Fill Medium Dense Surficial Soils 0 to 3.5 feet Lean Clay, Sandy Lean Clay Medium Stiff to Hard Intermediate SoiIS2 2 to 9 feet Sandy Silty Clay Very Stiff to Hard Deeper Soils 6 to 15 feet Poorly Graded Gravel with Sand, Silty Medium Dense to Sand Very Dense 'Fills only encountered in test pit 2. 2Calcium carbonate cementation encountered in portions of this horizon. During excavation, sloughing of test pit sidewalls was observed. In general, fine-grained soils remained stable while more granular sediments readily sloughed. However, moisture contents will also affect wall competency with saturated soils having a tendency to readily slough when under load and unsupported. 4.4 Volatile Organic Scan Soils obtained during on-site activities were not assessed for volatile organic compounds by portable photoionization detector. Samples obtained during our exploration activities exhibited no apparent odors or discoloration typically associated with this type of contamination. No groundwater was encountered. Atlas No. B231179g Page 15 Copyright©2023 Atlas Technical Consultants �TrT-G7T�", 5. SITE HYDROLOGY Existing surface drainage conditions are defined in the General Site Characteristics section. Information provided in this section is limited to observations made at the time of the investigation. Either regional or local ordinances may require information beyond the scope of this report. 5.1 Groundwater During this field investigation, groundwater was not encountered in test pits advanced to a maximum depth of 14.8 feet bgs. Atlas has previously performed 6 geotechnical investigations within 0.35 mile of the project site. Information from these investigations has been provided in the table below. Table 3— Groundwater Data Approximate Distance k Lundwater Depth Direction from Site f from Site (mile) A feet • . September 2015 0.11 Northeast Not Encountered to 15.5 September 2022 0.11 North Not Encountered to 15.2 September 2021 0.16 North Not Encountered to 15.2 December 2011 0.22 Northwest Not Encountered to 21.5 November 2019 0.13 West Not Encountered to 12.0 May 2018 0.13 West Not Encountered to 15.6 Based on evidence of this investigation and background knowledge of the area, Atlas has determined that the typical seasonal high groundwater should remain greater than approximately 20 feet bgs. This depth can be confirmed through long-term groundwater monitoring. )oil Infiltration Rates Soil permeability, which is a measure of the ability of a soil to transmit a fluid, was not tested in the field. Given the absence of direct measurements, for this report an estimation of infiltration is presented using generally recognized values. Typical infiltration rates comprising the generalized soil profile for this study have been provided in the table below. Atlas No. B231179g Page 16 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. Table 4—Generalized Soil Infiltration Rates Typical Infiltratio Soil Type Rate (inches per hour] Lean Clay <2 Sandy Lean Clay Sandy Silty Clay <2 to 4* Silty Sand 4 to 8 Poorly Graded Gravel with Sand >12 *The presence of cementation/induration may reduce infiltration rates to near zero. It is recommended that infiltration facilities constructed on the site be extended into native poorly graded gravel with sand sediments. Excavation depths ranging from approximately 6 to 9 feet bgs should be anticipated to expose these poorly graded gravel with sand sediments. An infiltration rate of 8 inches per hour should be used in design. Actual infiltration rates should be confirmed at the time of construction. Atlas recommends that all infiltration facilities be constructed in accordance with the local municipality requirements. LATERAL EARTH PRESSURES Retaining walls will be subject to lateral earth pressures. The magnitude of earth pressure is a function of both type and compaction of backfill behind walls within the "active" zone, and allowable rotation of the top of the wall. The active zone is defined as the wedge of soil between the surface of the wall and a plane inclined 31 degrees from vertical passing through the base of the wall. All clay soils must be completely removed from within the active zone. When dealing with lateral earth pressures on a gravity block the following sliding frictional coefficients should be used: For native sandy silty clay soils use 0.35. For native poorly graded gravel with sand sediments and imported granular structural fill use 0.45. Restrained walls, such as basement walls, should be designed based on at-rest pressures. Active pressures are appropriate under conditions where the wall moves or rotates away from the soil mass at failure. Passive pressures are used for conditions where the wall moves toward the soil mass at failure. Rotation, or lateral movement, of the top of the wall equal to 0.002 times the height of the wall will be necessary for on-site soil backfill to achieve an "active" loading condition. Lateral movement of the top of the wall equal to 0.001 times the height of the wall will be necessary for the "active" pressure condition for imported granular structural backfill. Atlas No. B231179g Page 17 Copyright©2023 Atlas Technical Consultants 6.1 Retaining Wall Backfill Materials Atlas anticipates that backfill materials will consist of the onsite native poorly graded gravel with sand sediments. Clayey soils are not suitable for use as backfill on the soil side of walls. The following values are applicable under non-surcharged, drained conditions. Table 5— Lateral Earth Pressure Values Internal Friction Angle: 35 ° Dry Unit Weight: 128 pcf Cohesion: N/A Bouyant Unit Weight: 83 pcf Natural Void Ratio: 0.4 Moisture Content: 5 % Ground Acceleration2: 0.201 Backfill Slope: 0 ° At rest lateral earth pressure: 57 pcf' Ko= 0.43 Active lateral earth pressure: 36 pcf' Ka= 0.27 Passive lateral earth pressure: 496 pcf' Kp= 3.69 Seismic active lateral earth pressure: 57 pcf' Kae= 0.42 Seismic passive lateral earth pressure: 396 pcf' Kpe= 2.95 'Lateral earth pressure values are in pounds per square foot,per foot of wall(psf/ft). Alternately,the values presented may also be considered as equivalent fluid with units of pounds per cubic foot(pcf). 2Ground acceleration obtained from the USGS Seismic Design Maps. Note that the values for seismic lateral earth pressures are calculated using both the static and seismic coefficients. The effect of seismic conditions alone is the difference between the static and seismic lateral earth pressures presented above. In the case that another material is used for backfill, Atlas should be consulted for alternate lateral earth pressure values. Granular structural fill should consist of 4-inch-minus select, clean, granular soil with no more than 30 percent oversize (greater than 3/4-inch) material and no more than 5 percent non-plastic fines (passing the No. 200 sieve). Retaining wall backfill must be placed in accordance with recommendations in the Fill Placement and Compaction section of this report and must be properly compacted and tested. Lateral earth pressure values do not incorporate specific factors of safety, and are only applicable for non-surcharged, drained conditions. Factors of safety, if applicable, should be integrated into the structural design of the wall. Furthermore, changes in soil moisture, such as can be imposed by site stormwater systems, can change the values listed above. The preceding values are presented for idealized conditions relating to simple shallow structures. For complex structures, deep structures, or structures with significant perimeter landscaping, a soils engineer should be retained as part of the design team in developing appropriate project design parameters and construction specifications. Atlas No. 13231179g Page 18 Copyright©2023 Atlas Technical Consultants �TrT-G7T��. 6.2 Retaining Wall Drainage Atlas recommends that a drainage system be incorporated into the retained soil mass. This can be accomplished by installing wall and toe drains as a part of each soil-supporting wall system. The drainage system should consist of the following: • A 2-foot wide section of drain rock should be placed immediately behind the wall. A compacted, low-permeability soil cap is recommended within the upper 2 feet of the surface to limit surface water infiltration behind the walls. If hardscaping is present, the low-permeability soil cap can be eliminated. • A 4-inch diameter perforated drain pipe should be installed at the footing elevation of each wall. This pipe must slope at least 1 percent to a suitable discharge point away from the wall. These drainage systems must be separate from other retaining wall/foundation systems, such as roof drain effluent and irrigation water systems. 7. FOUNDATION AND SLAB DISCUSSION AND RECOMMENDATIONS Various foundation types have been considered for support of the proposed development. Two requirements must be met in the design of foundations. First, the applied bearing stress must be less than the ultimate bearing capacity of foundation soils to maintain stability. Second, total and differential settlement must not exceed an amount that will produce an adverse behavior of the superstructure. Allowable settlement is usually exceeded before bearing capacity considerations become important; thus, allowable bearing pressure is normally controlled by settlement considerations. 7.1 Foundation Loading Information Loads of up to 4,000 pounds per lineal foot for wall footings, and column loads of up to 50,000 pounds were assumed for settlement calculations. Total settlement should be limited to approximately 1 inch and differential settlement should be limited to approximately '/2 inch, provided the following design and construction recommendations are observed. 7.2 Foundation Design Recommendations Considering subsurface conditions and the proposed construction, it is recommended that the structures be founded upon conventional spread footings and continuous wall footings. The following recommendations are not specific to the individual structures, but rather should be viewed as guidelines for the subdivision-wide development. Based on data obtained from the site and test results from various laboratory tests performed, Atlas recommends the following guidelines for the net allowable soil bearing capacity: Atlas No. B231179g Page 19 Copyright©2023 Atlas Technical Consultants Table 6— Soil Bearing Capacity Footing Depth ASTM D1557 Net Allowable Soil Subgrade CompactionCapacity Footings must bear on competent, undisturbed, 1,5001bs/ft2 native lean clay soils or sandy lean clay soils. Not Required for Native A'/3 increase is allowable Organic materials and fill materials must be Soil if the alternative basic completely removed from below foundation load combinations of elements.' Excavation depths ranging from roughly 95% for Structural Fill Section 1605.3.2 of the 0.2 to 1.5 feet bgs should be anticipated to expose 2018 IBC are used in proper bearing soils.2 design. Footings must bear on competent, undisturbed, native sandy silty clay soils, poorly graded gravel with sand sediments, or compacted structural fill. Not Required for Native Existing lean clay soils, sandy lean clay soils, Soil 2,000Ibs/ft2 organic materials, and fill materials must be completely removed from below foundation 95% for Structural Fill elements.' Excavation depths ranging from roughly 2.0 to 3.3 feet bgs should be anticipated to expose proper bearing soils.2 'It will be required for Atlas personnel to verify the bearing soil suitability for each structure at the time of construction. 2Depending on the time of year construction takes place,the subgrade soils may be unstable because of high moisture contents. If unstable conditions are encountered,over-excavation and replacement with granular structural fill and/or use of geotextiles may be required. The following sliding frictional coefficient values should be used: 1) 0.35 for footings bearing on native lean clay soils, sandy lean clay soils, and sandy silty clay soils and 2) 0.45 for footings bearing on native poorly graded gravel with sand sediments and granular structural fill. A passive lateral earth pressure of 312 pounds per square foot per foot (psf/ft) should be used for lean clay and sandy lean clay soils. A passive lateral earth pressure of 335 pounds per square foot per foot (psf/ft) should be used for sandy silty clay soils. For native poorly graded gravel with sand sediments and compacted sandy gravel fill, a passive lateral earth pressure of 496 psf/ft should be used. Footings should be proportioned to meet either the stated soil bearing capacity or the 2018 IBC minimum requirements. Objectionable soil types encountered at the bottom of footing excavations should be removed and replaced with structural fill. Excessively loose or soft areas that are encountered in the footings subgrade will require over-excavation and backfilling with structural fill. To minimize the effects of slight differential movement that may occur because of variations in the character of supporting soils and seasonal moisture content, Atlas recommends continuous footings be suitably reinforced to make them as rigid as possible. For frost protection, the bottom of external footings should be 24 inches below finished grade. Foundations must be backfilled in accordance with the Backfill of Walls section. Atlas No. B231179g Page110 Copyright©2023 Atlas Technical Consultants �TrT-G7T�1 7.3 Floor Slab-on-Grade Uncontrolled fill was encountered in the vicinity of test pit 2. Atlas recommends that these fill materials be completely removed. Once final grades have been determined, Atlas is available to provide additional recommendations. Organic, loose, or obviously compressive materials must be removed prior to placement of concrete floors or floor-supporting fill. In addition, the remaining subgrade should be treated in accordance with guidelines presented in the Earthwork section. Areas of excessive yielding should be excavated and backfilled with structural fill. Fill used to increase the elevation of the floor slab should meet requirements detailed in the Structural Fill section. Fill materials must be compacted to a minimum 95 percent of the maximum dry density as determined by ASTM D1557. A free-draining granular mat should be provided below slabs-on-grade to provide drainage and a uniform and stable bearing surface. This should be a minimum of 4 inches in thickness and properly compacted. The mat should consist of a sand and gravel mixture, complying with Idaho Standards for Public Works Construction (ISPWC) specifications for 3/4-inch (Type 1) crushed aggregate. The granular mat should be compacted to no less than 95 percent of the maximum dry density as determined by ASTM D1557. A moisture-retarder should be placed beneath floor slabs to minimize potential ground moisture effects on moisture-sensitive floor coverings. The moisture-retarder should be at least 15-mil in thickness and have a permeance of less than 0.01 US perms as determined by ASTM E96. Placement of the moisture-retarder will require special consideration with regard to effects on the slab-on-grade and should adhere to recommendations outlined in the ACI 302.1 R and ASTM E1745 publications. Upon request, Atlas can provide further consultation regarding installation. 8. CONSTRUCTION CONSIDERATIONS 8.1 Earthwork Excessively organic soils, deleterious materials, or disturbed soils generally undergo high volume changes when subjected to loads, which is detrimental to subgrade behavior in the area of pavements, floor slabs, structural fills, and foundations. Brush and thick grasses with associated root systems were noted at the time of our investigation. It is recommended that organic or disturbed soils, if encountered, be removed to depths of 0.5 foot (minimum), and wasted or stockpiled for later use. Stripping depths should be adjusted in the field to assure that the entire root zone or disturbed zone or topsoil are removed prior to placement and compaction of structural fill materials. Exact removal depths should be determined during grading operations by Atlas personnel, and should be based upon subgrade soil type, composition, and firmness or soil stability. If underground storage tanks, underground utilities, wells, or septic systems are discovered during construction activities, they must be decommissioned then removed or abandoned in accordance with governing Federal, State, and local agencies. Excavations developed as the result of such removal must be backfilled with structural fill materials as defined in the Structural Fill section. Atlas No. B231179g Page111 Copyright©2023 Atlas Technical Consultants �rrN+=0 A�1. Atlas should oversee subgrade conditions (i.e., moisture content) as well as placement and compaction of new fill (if required) after native soils are excavated to design grade. Recommendations for structural fill presented in this report can be used to minimize volume changes and differential settlements that are detrimental to the behavior of footings, pavements, and floor slabs. Sufficient density tests should be performed to properly monitor compaction. 8.2 Grading Positive grades must be maintained surrounding structures and pavements, including exterior slabs. The interface of plant bedding materials and underlying soils should be graded to provide drainage away from site elements. Otherwise, bedding materials may direct water to underlying fine-grained soils, which increases the potential for localized heave. Excessive watering of landscaping should be avoided. If structures are to be tightly clustered, limiting space between two adjacent foundation systems, subsurface drains may be required to alleviate water ponding during short, intense storm events. 8.3 Dry Weather If construction is to be conducted during dry seasonal conditions, many problems associated with soft soils may be avoided. However, some rutting of subgrade soils may be induced by shallow groundwater conditions related to springtime runoff or irrigation activities during late summer through early fall. Solutions to problems associated with soft subgrade soils are outlined in the Soft Sub-grade Soils section. Problems may also arise because of lack of moisture in native and fill soils at time of placement. This will require the addition of water to achieve near-optimum moisture levels. Low-cohesion soils exposed in excavations may become friable, increasing chances of sloughing or caving. Measures to control excessive dust should be considered as part of the overall health and safety management plan. 8.4 Wet Weather If construction is to be conducted during wet seasonal conditions (commonly from mid-November through May), problems associated with soft soils must be considered as part of the construction plan. During this time of year, fine-grained soils such as silts and clays will become unstable with increased moisture content, and eventually deform or rut. Additionally, constant low temperatures reduce the possibility of drying soils to near optimum conditions. 8.5 Soft Subgrade Soils Shallow fine-grained subgrade soils that are high in moisture content should be expected to pump and rut under construction traffic. During periods of wet weather, construction may become very difficult if not impossible. The following recommendations and options have been included for dealing with soft subgrade conditions: Atlas No. B231179g Page112 Copyright©2023 Atlas Technical Consultants • Track-mounted vehicles should be used to strip the subgrade of root matter and other deleterious debris. Heavy rubber-tired equipment should be prohibited from operating directly on the native subgrade and areas in which structural fill materials have been placed. Construction traffic should be restricted to designated roadways that do not cross, or cross on a limited basis, proposed roadway or parking areas. • Soft areas can be over-excavated and replaced with granular structural fill. • Construction roadways on soft subgrade soils should consist of a minimum 2-foot thickness of large cobbles of 4 to 6 inches in diameter with sufficient sand and fines to fill voids. Construction entrances should consist of a 6-inch thickness of clean, 2-inch minimum, angular drain-rock and must be a minimum of 10 feet wide and 30 to 50 feet long. During the construction process, top dressing of the entrance may be required for maintenance. • Scarification and aeration of subgrade soils can be employed to reduce the moisture content of wet subgrade soils. After stripping is complete, the exposed subgrade should be ripped or disked to a depth of 1'/z feet and allowed to air dry for 2 to 4 weeks. Further disking should be performed on a weekly basis to aid the aeration process. • Alternative soil stabilization methods include use of geotextiles, lime, and cement stabilization. Atlas is available to provide recommendations and guidelines at your request. 8.6 Frozen Subgrade Soils Prior to placement of structural fill materials or foundation elements, frozen subgrade soils must either be allowed to thaw or be stripped to depths that expose non-frozen soils and wasted or stockpiled for later use. Stockpiled materials must be allowed to thaw and return to near-optimal conditions prior to use as structural fill. The onsite, shallow clayey and silty soils are susceptible to frost heave during freezing temperatures. For exterior flatwork and other structural elements, adequate drainage away from subgrades is critical. Compaction and use of structural fill will also help to mitigate the potential for frost heave. Complete removal of frost susceptible soils for the full frost depth, followed by replacement with a non-frost susceptible structural fill, can also be used to mitigate the potential for frost heave. Atlas is available to provide further guidance/assistance upon request. Atlas No. B231179g Page113 Copyright©2023 Atlas Technical Consultants �TrT-G7T�1 8.7 Structural Fill The following table defines the types of fill material that is suitable for use on the project. Refer to the Fill Placement and Compaction section for recommended placement locations for each fill type listed below. Table 7— Fill Material Criteria Fill Type LiftThickness* J 1L ISPWC Section 801 for 1-inch, 3-inch, or 6- Granular Structural Fill inch Uncrushed Aggregate and 12 inches ISPWC Section 802 Aggregate Base Aggregate Base Material ISPWC Section 802 for Type 1 Crushed 12 inches Aggregate Base Subbase Material ISPWC Section 801 for 3-inch or 6-inch 12 inches Uncrushed Aggregate Suitable Structural Fill Onsite/imported ML, SM, and GM soils that 6 inches are free of organics and debris Suitable Soil Onsite/imported CL and CL-ML soils that are 6 inches free of organics and debris *Initial loose thickness,prior to compaction. 8.8 Fill Placement and Compaction Requirements for fill material type and compaction effort are dependent on the planned use of the material. The following table specifies material type and compaction requirements based on the placement location of the fill material. Table 8 — Fill Placement and Compaction Requirements Fill Loca iog§nWaterial Tymmwnw Compaction Foundations Granular Structural Fill 95% of ASTM D1557 Interior Slab-on-Grade Granular Structural Fill or 95% of ASTM D1557 Suitable Structural Fill Top 4 Inches of Interior and Exterior Aggregate Base Material 95% of ASTM D1557 Slab-on-Grade Below Flexible Pavement Subgrade Granular Structural Fill or 95% of ASTM D698 or and Exterior Flatwork Areas Suitable Structural Fill 92% of ASTM D1557 Foundation and Retaining Wall Granular Structural Fill or 95% of ASTM D1557 Backfill Suitable Structural Fill Utility Trench Backfill Granular Structural Fill or Per ISPWC Section 306 Suitable Soil Landscape Areas Granular Structural Fill or 92% of ASTM D698 or Suitable Soil 90/o of ASTM D1557 Atlas No. B231179g PageJ14 Copyright©2023 Atlas Technical Consultants Prior to placement of structural fill materials, surfaces must be prepared as outlined in the Earthwork section. Structural fill material must be placed in horizontal lifts not exceeding 6- inches in thickness for fine-grained soils and 12-inches in thickness for granular structural fill, aggregate base material, and subbase material. All fill material must be moisture-conditioned to achieve optimum moisture content prior to compaction. During placement all fill materials must be monitored and tested to confirm compaction requirements have been achieved, as specified above, prior to placement of subsequent lifts. In addition, compacted surfaces must be in a firm and unyielding condition. Atlas personnel should be onsite to verify suitability of subgrade soil conditions, identify whether further work is necessary, and perform in-place moisture density testing. Sufficient density tests should be performed to properly monitor compaction. At a minimum, Atlas recommends one test per lift as follows: • Structures— 1 test every 5,000 square feet • Pavement and Exterior Flatwork Areas — 1 test every 10,000 square feet • Foundation and Retaining Wall Backfill — 1 test every 500 square feet • Utility Trench Backfill — 1 test every 100 linear feet • Landscape Areas — 1 test every 15,000 square feet Silty soils require very high moisture contents for compaction, require a long time to dry out if natural moisture contents are too high, and may also be susceptible to frost heave under certain conditions. Therefore, these materials can be quite difficult to work with as moisture content, lift thickness, and compactive effort becomes difficult to control. If silty soil is used for structural fill, lift thicknesses should not exceed 6 inches (loose), and fill material moisture must be closely monitored at both the working elevation and the elevations of materials already placed. Following placement, the exposed surface must be protected from degradation resulting from construction traffic or subsequent construction. It is anticipated that fine-grained soils will not be suitable for reuse during the wet season. Use of silty soils (GM, SM, and ML) as structural fill below footings is prohibited. For structural fill below footings, areas of compacted backfill must extend outside the perimeter of the footings for a distance equal to the thickness of fill between the bottom of foundation and underlying soils, or 5 feet, whichever is less. If material contains more than 40 percent but less than 50 percent oversize (greater than %-inch) particles, compaction of fill must be confirmed per ISPWC Section 202.3.8.D.3. Material should contain sufficient fines to fill void spaces and must not contain more than 50 percent oversize particles. Atlas No. B231179g Page115 Copyright©2023 Atlas Technical Consultants 8.9 Backfill of Walls Backfill materials must conform to the requirements of structural fill, as defined in this report. For wall heights greater than 2.5 feet, the maximum material size should not exceed 4 inches in diameter. Placing oversized material against rigid surfaces interferes with proper compaction and can induce excessive point loads on walls. Backfill shall not commence until the wall has gained sufficient strength to resist placement and compaction forces. Further, retaining walls above 2.5 feet in height shall be backfilled in a manner that will limit the potential for damage from compaction methods and/or equipment. It is recommended that only small hand-operated compaction equipment be used for compaction of backfill within a horizontal distance equal to the height of the wall, measured from the back face of the wall. Backfill should be compacted in accordance with the specifications for structural fill, except in those areas where it is determined that future settlement is not a concern, such as planter areas. In nonstructural areas, backfill must be compacted to a firm and unyielding condition. Atlas recommends in these areas that the top 12 inches must consist of a low permeability (clay or silt) soil to limit surface water infiltration. Proper grading away from structures is critical. The surface must be graded away from the structure. In addition, Atlas recommends that roof drains carry stormwater at least 10 feet away from the structure. 8.10 Excavations Shallow excavations that do not exceed 4 feet in depth may be constructed with side slopes approaching vertical. Below this depth, it is recommended that slopes be constructed in accordance with Occupational Safety and Health Administration (OSHA) regulations, Section 1926, Subpart P. Based on these regulations, on-site soils are classified as type "C" soil, and as such, excavations within these soils should be constructed at a maximum slope of 1'/2 feet horizontal to 1 foot vertical (1'/2:1) for excavations up to 20 feet in height. Excavations in excess of 20 feet will require additional analysis. Note that these slope angles are considered stable for short-term conditions only, and will not be stable for long-term conditions. During the subsurface exploration, test pit sidewalls generally exhibited little indication of collapse; however, sloughing of fill materials and native granular sediments from test pit sidewalls was observed. For deep excavations, native granular sediments cannot be expected to remain in position. These materials are prone to failure and may collapse, thereby undermining upper soil layers. This is especially true when excavations approach depths near the water table. Care must be taken to ensure that excavations are properly backfilled in accordance with procedures outlined in this report. Atlas No. B231179g Page116 Copyright©2023 Atlas Technical Consultants �TrT-G7T�1 8.11 Groundwater Control Special precautions may be required for control of surface runoff and subsurface seepage. It is recommended that runoff be directed away from open excavations. Silty and clayey soils may become soft and pump if subjected to excessive traffic during time of surface runoff. Ponded water in construction areas should be drained through methods such as trenching, sloping, crowning grades, nightly smooth drum rolling, or installing a French drain system. Additionally, temporary or permanent driveway sections should be constructed if extended wet weather is forecasted. GENERAL COMMENTS Based on the subsurface conditions encountered during this investigation and available information regarding the proposed development, the site is adequate for the planned construction. When plans and specifications are complete, and if significant changes are made in the character or location of the proposed development, consultation with Atlas must be arranged as supplementary recommendations may be required. Suitability of subgrade soils and compaction of structural fill materials must be verified by Atlas personnel prior to placement of structural elements. Additionally, monitoring and testing should be performed to verify that suitable materials are used for structural fill and that proper placement and compaction techniques are utilized. Atlas No. B231179g Page117 Copyright©2023 Atlas Technical Consultants 10. REFERENCES American Concrete Institute (ACI) (2015). Guide for Concrete Floor and Slab Construction: ACI 302.11R. Farmington Hills, MI: ACI. American Society of Civil Engineers (2021). ASCE 7 Hazards Tool: Web Interface. [Online] Available: <https://asce7hazardtool.online/> (2023). American Society of Civil Engineers (ASCE) (2017). Minimum Design Loads for Buildings and Other Structures: ASCE/SEI 7-16. Reston, VA: ASCE. American Society for Testing and Materials (ASTM) (2017). Standard Test Method for Materials Finer than 75-um (No. 200) Sieve in Mineral Aggregates by Washing: ASTM C117. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2019). Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates: ASTM C136. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2021). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort: ASTM D698. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2021). Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort: ASTM D1557. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2017). Standard Practice for Classification of Soils for Engineering Purposes(Unified Soil Classification System):ASTM D2487.West Conshohocken, PA:ASTM. American Society for Testing and Materials (ASTM) (2017). Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils: ASTM D4318. West Conshohocken, PA: ASTM. American Society for Testing and Materials (ASTM) (2017). Standard Specification for Plastic Water Vapor Retarders Used in Contact with Soil or Granular Fill Under Concrete Slabs: ASTM E1745. West Conshohocken, PA: ASTM. International Building Code Council (2018). International Building Code. Country Club Hills, IL: Author. Local Highway Technical Assistance Council (LHTAC) (2020). Idaho Standards for Public Works Construction. Boise, ID: Author. Othberg, K. L. and Stanford, L. A., Idaho Geologic Society (1993). Geologic Map of the Boise Valley and Adjoining Area, Western Snake River Plain, Idaho. (scale 1:100,000). Boise, ID: Joslyn and Morris. U.S. Department of Labor, Occupational Safety and Health Administration 2020 . CFR 29, Part 1926, Subpart P Appendix A: Safety and Health Regulations for Construction, Excavations. Washington D.C.: OSHA. Atlas No. B231179g Page118 Copyright©2023 Atlas Technical Consultants �TrT-G7T_�. APPENDIX I WARRANTY AND LIMITING CONDITIONS Atlas warrants that findings and conclusions contained herein have been formulated in accordance with generally accepted professional engineering practice in the fields of foundation engineering, soil mechanics, and engineering geology only for the site and project described in this report. These engineering methods have been developed to provide the client with information regarding apparent or potential engineering conditions relating to the site within the scope cited above and are necessarily limited to conditions observed at the time of the site visit and research. Field observations and research reported herein are considered sufficient in detail and scope to form a reasonable basis for the purposes cited above. Exclusive Use This report was prepared for exclusive use of the property owner(s), at the time of the report, and their retained design consultants ("Client"). Conclusions and recommendations presented in this report are based on the agreed-upon scope of work outlined in this report together with the Contract for Professional Services between the Client and Atlas Technical Consultants ("Consultant"). Use or misuse of this report, or reliance upon findings hereof, by parties other than the Client is at their own risk. Neither Client nor Consultant make representation of warranty to such other parties as to accuracy or completeness of this report or suitability of its use by such other parties for purposes whatsoever, known or unknown, to Client nor Consultant. Neither Client nor Consultant shall have liability to indemnify or hold harmless third parties for losses incurred by actual or purported use or misuse of this report. No other warranties are implied or expressed. Report Recommendations are Limited and Subject to Misinterpretation There is a distinct possibility that conditions may exist that could not be identified within the scope of the investigation or that were not apparent during our site investigation. Findings of this report are limited to data collected from noted explorations advanced and do not account for unidentified fill zones, unsuitable soil types or conditions, and variability in soil moisture and groundwater conditions. To avoid possible misinterpretations of findings, conclusions, and implications of this report, Atlas should be retained to explain the report contents to other design professionals as well as construction professionals. Since actual subsurface conditions on the site can only be verified by earthwork, note that construction recommendations are based on general assumptions from selective observations and selective field exploratory sampling. Upon commencement of construction, such conditions may be identified that require corrective actions, and these required corrective actions may impact the project budget. Therefore, construction recommendations in this report should be considered preliminary, and Atlas should be retained to observe actual subsurface conditions during earthwork construction activities to provide additional construction recommendations as needed. Atlas No. B231179g Page119 Copyright©2023 Atlas Technical Consultants Since geotechnical reports are subject to misinterpretation, do not separate the soil logs from the report. Rather, provide a copy of, or authorize for their use, the complete report to other design professionals or contractors. Locations of exploratory sites referenced within this report should be considered approximate locations only. For more accurate locations, services of a professional land surveyor are recommended. This report is also limited to information available at the time it was prepared. In the event additional information is provided to Atlas following publication of our report, it will be forwarded to the client for evaluation in the form received. Environmental Concerns Comments in this report concerning either onsite conditions or observations, including soil appearances and odors, are provided as general information. These comments are not intended to describe, quantify, or evaluate environmental concerns or situations. Since personnel, skills, procedures, standards, and equipment differ, a geotechnical investigation report is not intended to substitute for a geoenvironmental investigation or a Phase II/III Environmental Site Assessment. If environmental services are needed, Atlas can provide, via a separate contract, those personnel who are trained to investigate and delineate soil and water contamination. Atlas No. B231179g Page120 Copyright©2023 Atlas Technical Consultants Vicinity Map Figure 1 �4 Cd.jI MAP NOTES: •Not to Scale 6a:y+nti.k can 21 a1 0 w Smote S= y`9 far�.e yIry V Q Y44 LEGEND Approximate Site Location Eagle island Statc Pzrk CatV" M&nn CaO n Can 55 i Boise C Canal -� rn ry Club Phytlia Canal 3anbury Galf Club m _W Chinden Blvd 1 ie: is E Chinden Blvd zo! E Chinden Blvd n z CL Saciarra Subdivision 913&1241 West Orchard Park Drive Meridian,ID ite Location Modified by:CRM July 24,2023 Lowell Drawing:B231179 Scott 9� 9 Middle School Letup Canal Len I'Car-t Pioneer _r T ■ flemewen�ary School 2791 S.Victory View Way Phone: (208)376-4748 Boise,ID 83709 Fax: (208)322-6515 03U33 Mitt 1023 TomTom� Web: oneatlas.com Site Map Figure 2 i r t i Z.'fit soft TP-2 ORCHARD PA TP-3 01 TP-7 TP-5 TP-6 '_ TP-4 8 • D z ■■ �a < w f �. f —r i m z ,c m 6 4f all • NOTES: LEGEND Saciarra Subdivision •Not to Scale Approximate Site 913&1241 West Orchard Park Drive �II /�� �► Boundary Meridian,ID Modified by:CRM 2791 S.Victory View Way Phone: (208)376-4748 Approximate Atlas Test Boise,ID 83709 Fax: (208)322-6515 Pit Location 8 July 24,2023 Web: oneatlas.cwm Drawing:B231179g APPENDIX IV GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-1 Latitude: 43.659629 Date Advanced: July 17, 2023 Longitude: -116.404401 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Alexander Hanle Total Depth: 14.0 feet bgs Depth . Description and USCS Soil • .$) Sediment Classification . bgs) QP Test ID Lean Clay (CL): Dark brown, dry, hard. 0.0-2.4 --Organic material encountered to 0.9 foot 4.5+ bgs. Sandy Silty Clay (CL-ML): Brown to light brown, dry to slightly moist, very stiff to hard, with fine to coarse-grained sand. 2.4-7.0 --Weak to moderate calcium carbonate 4.0-4.5 cementation from 2.4 to 6.2 feet bgs. --Moderate to strong calcium carbonate cementation encountered from 6.2 to 7.0 feet bgs. Poorly Graded Gravel with Sand (GP): Brown to light brown, slightly moist, medium dense to 7.0-14.0 very dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Atlas No. B231179g Page123 Copyright©2023 Atlas Technical Consultants �TrT-G7T�1 GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-2 Latitude: 43.659117 Date Advanced: July 17, 2023 Longitude: -116.402400 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Alexander Hanle Total Depth: 14.4 feet bgs Depth ieldd Description and USCS Soil and Sample Sample Depth Qp Lab ••s) Sediment Classification • •• Clayey Gravel with Sand Fill(GC-FILL): Brown to light brown, dry to slightly moist, medium 0.0-1.5 dense, with fine to coarse-grained sand and fine gravel. --Organic material encountered to 0.7 foot bgs. 1.5-3.0 Lean Clay (CL): Dark brown, slightly moist, 4.0-4.5+ very stiff to hard. Sandy Silty Clay (CL-ML): Brown to light brown, slightly moist, very stiff to hard, with 3.0-7.1 fine to coarse-grained sand. 4.0-4.5+ --Weak to moderate calcium carbonate cementation encountered throughout. Poorly Graded Gravel with Sand (GP): Brown to light brown, slightly moist, medium dense to 7.1-14.4 very dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. Notes:See Site Map for test pit location. Atlas No. B231179g Page 124 Copyright©2023 Atlas Technical Consultants �TrT-G7T�1 GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-3 Latitude: 43.660106 Date Advanced: July 17, 2023 Longitude: -116.405378 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Alexander Hanle Total Depth: 14.3 feet bgs Depth ieldd Description and USCS Soil and Sample Sample Depth Qp Lab ••s) Sediment Classification • •• inCi Lean Clay(CL): Brown to light brown, dry,very 0.0-2.8 stiff to hard. 3.75- --Organic material encountered to 0.3 foot 4.5+ bgs. Sandy Silty Clay (CL-ML): Brown to light brown, dry, very stiff to hard, with fine to coarse-grained sand. --Weak to moderate calcium carbonate 2.8-6.8 cementation encountered from 2.8 to 4.5 feet 4.0-4.5+ bgs. --Moderate to strong calcium carbonate cementation encountered from 4.5 to 6.8 feet bgs. Poorly Graded Gravel with Sand (GP): Brown to light brown, dry to slightly moist, dense to 6.8-14.3 very dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. --Sidewall sloughing noted throughout. Notes:See Site Map for test pit location. Atlas No. B231179g Page 125 Copyright©2023 Atlas Technical Consultants �TrT-G7T�1 GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-4 Latitude: 43.659524 Date Advanced: July 17, 2023 Longitude: -116.406306 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Alexander Hanle Total Depth: 14.2 feet bgs Depth ieldd Description and USCS Soil and Sample Sample Depth Qp Lab ••s) Sediment Classification • •• inCi Lean Clay (CL): Brown, dry, very stiff. 0.0-3.3 --Organic material encountered to 0.3 foot GS 1.0-2.0 2.25-3.0 A bgs. Sandy Silty Clay (CL-ML): Brown to light brown, slightly moist, very stiff to hard, with 3.3-5.8 fine to coarse-grained sand. 4.0-4.5+ --Weak calcium carbonate cementation encountered throughout. Poorly Graded Gravel with Sand (GP): Brown to light brown, slightly moist, dense, with fine 5.8-14.2 to coarse-grained sand, fine to coarse gravel, and 10-inch minus cobbles. --Sidewall sloughing noted throughout. Notes:See Site Map for test pit location. A 13.6 28 8 100 100 98 95 90.8 Atlas No. B231179g Page 126 Copyright©2023 Atlas Technical Consultants �TrT-G7T�1 GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-5 Latitude: 43.659819 Date Advanced: July 17, 2023 Longitude: -116.407496 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Alexander Hanle Total Depth: 14.8 feet bgs Depth ieldd Description and USCS Soil and Sample Sample Depth Qp Lab ••s) Sediment Classification • •• Lean Clay (CL): Brown, slightly moist, stiff to 0.0-2.0 very stiff. 2.0-2.5 --Organic material encountered to 0.3 foot bgs. Sandy Silty Clay (CL-ML): Brown to light brown, slightly moist, very stiff to hard, with fine to coarse-grained sand. --Weak to moderate calcium carbonate 2.0-7.7 cementation encountered from 2.0 to 5.0 feet 4.0-4.5+ bgs. --Moderate to strong calcium carbonate cementation encountered from 5.0 to 7.7 feet bgs. Poorly Graded Gravel with Sand (GP): Brown to light brown, slightly moist, medium dense to 7.7-14.8 dense, with fine to coarse-grained sand, fine to coarse gravel, and 6-inch minus cobbles. --Sidewall sloughing noted throughout. Notes:See Site Map for test pit location. Atlas No. B231179g Page 127 Copyright©2023 Atlas Technical Consultants �TrT-G7T�1 GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-6 Latitude: 43.659644 Date Advanced: July 17, 2023 Longitude: -116.408993 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Alexander Hanle Total Depth: 13.3 feet bgs Depth ieldd Description and USCS Soil and Sample Sample Depth Qp Lab ••s) Sediment Classification • •• Sandy Lean Clay (CL): Brown, dry to slightly moist, medium stiff to stiff,with fine to medium- 0.0-2.4 grained sand. 0.75-1.0 --Organic material encountered to 0.3 foot bgs. Sandy Silty Clay (CL-ML): Brown to light 2.4-9.0 brown, slightly moist, hard, with fine to coarse- 4.5+ grained sand. Poorly Graded Gravel with Sand (GP): Brown to light brown, slightly moist, dense to very 9.0-12.5 dense, with fine to coarse grained sand, fine to coarse gravel, and 5-inch minus cobbles. --Sidewall sloughing noted throughout. Silty Sand (SM): Brown to light brown, slightly 12.5-13.3 moist, dense to very dense, with fine to coarse-grained sand and fine gravel. Notes:See Site Map for test pit location. Atlas No. 13231179g Page 128 Copyright©2023 Atlas Technical Consultants �TrT-G7T�1 GEOTECHNICAL INVESTIGATION TEST PIT LOG Test Pit Log #: TP-7 Latitude: 43.659769 Date Advanced: July 17, 2023 Longitude: -116.410109 Excavated by: Turn of the Century Homes Depth to Water Table: Not Encountered Logged by: Alexander Hanle Total Depth: 14.1 feet bgs Depth ieldd Description and USCS Soil and Sample Sample Depth Qp Lab ••s) Sediment Classification • •• Sandy Lean Clay (CL): Brown, dry to slightly moist, medium stiff to stiff,with fine to medium- 0.0-3.1 grained sand. 0.75-1.0 --Organic material encountered to 0.2 foot bgs. Sandy Silty Clay (CL-ML): Brown, dry to slightly moist, very stiff to hard, with fine- 3.1-6.7 grained sand. GS 3.5-4.0 4.0-4.5+ B --Weak to moderate calcium carbonate cementation encountered throughout. Poorly Graded Gravel with Sand (GP): Brown to light brown, slightly moist, medium dense to 6.7-14.1 dense, with fine to coarse-grained sand, fine to coarse gravel, and 5-inch minus cobbles. --Sidewall sloughing noted throughout. Notes:See Site Map for test pit location. • B 12.7 27 7 97 95 81 60 48.9 *Sieve results skewed due to cementation. Atlas No. B231179g Page 129 Copyright©2023 Atlas Technical Consultants �TrT-G7Tdr-W� APPENDIX V GEOTECHNICAL GENERAL NOTES Unified Soil Classification System Major Divisions Symbol Soil Descriptions Gravel & GW Well-graded ravels; ravel/sand mixtures with little or no fines Coarse- Gravelly Soils GP Poorly-graded ravels; ravel/sand mixtures with little or no fines Grained < 50% GM Silty gravels; poorly-graded ravel/sand/silt mixtures Soils < coarse GC Clayey gravels; poorly-graded gravel/sand/clay mixtures 50% Sand & Sandy SW Well-graded sands; gravelly sands with little or no fines passes Soils > 50% SP Poorl - raded sands; gravelly sands with little or no fines No.200 coarse SM Silty sands; poorly-graded sand/gravel/silt mixtures sieve fraction Sc Clayey sands; poorly-graded sand/gravel/clay mixtures Fine- ML Inorganic silts; sandy, gravellyor clayey silts Grained Silts & Clays CL Lean clays; inorganic, gravelly, sandy, or silty, low to medium- Soils > ILL < 50 plasticity clays 50% OL Organic, low-plasticity clays and silts passes MH Inorganic, elastic silts; sand ravel) or clayey elastic silts No.200 Silts &Clays CH Fat clays; high-plasticity, inorganic clays sieve ILL > 50 OH Organic, medium to high-plasticity clays and silts Highly Organic Soils PT Peat, humus, h dric soils with high organic content Relative Density • Consistency oisture Contentand Cementation • Class ificatlorWllllllllllllll, Coarse-Grained Soils SPT Blow Counts N Description Field Test Very Loose: <4 Dry Absence of moisture, dry to touch Loose: 4-10 Slightly Moist Damp, but no visible moisture Medium Dense: 10-30 Moist Visible moisture Dense: 30-50 Wet Visible free water Very Dense: > 50 Saturated Soil is usually below water table Fine-Grained Soils SPT Blow Counts N Description Field Test Very Soft: < 2 Weak Crumbles or breaks with handling or Soft: 2-4 slight finger pressure Medium Stiff: 4-8 Moderate Crumbles or breaks with Stiff: 8-15 considerable finger pressure Very Stiff: 15-30 Strong Will not crumble or break with finger Hard: > 30 pressure Particle Size ML Boulders: > 12 in. GS grab ample Cobbles: 12 to 3 in. ILL Liquid Limit Gravel: 3 in. to 5 mm M moisture content Coarse-Grained Sand: 5 to 0.6 mm NP non-plastic Medium-Grained Sand: 0.6 to 0.2 mm PI Plasticity Index Fine-Grained Sand: 0.2 to 0.075 mm Qp penetrometer value, unconfined compressive Silts: 0.075 to 0.005 mm strength, tsf Clays: < 0.005 mm V vane value, ultimate shearing strength, tsf Atlas No. B231179g Page 130 Copyright©2023 Atlas Technical Consultants IMPOPIOnt InfOPM81100 Rhout ■ GeolechnicalmEngineeping Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes. While you cannot eliminate all such risks, you can manage them. The following information is provided to help. The Geoprofessional Business Association (GBA) will not likely meet the needs of a civil-works constructor or even a has prepared this advisory to help you—assumedly different civil engineer.Because each geotechnical-engineering study a client representative—interpret and apply this is unique,each geotechnical-engineering report is unique,prepared geotechnical-engineering report as effectively as solely for the client. possible. In that way, you can benefit from a lowered Likewise,geotechnical-engineering services are performed for a specific exposure to problems associated with subsurface project and purpose.For example,it is unlikely that a geotechnical- conditions at project sites and development of engineering study for a refrigerated warehouse will be the same as them that,for decades, have been a principal cause one prepared for a parking garage;and a few borings drilled during of construction delays, cost overruns, claims, a preliminary study to evaluate site feasibility will not be adequate to and disputes. If you have questions or want more develop geotechnical design recommendations for the project. information about any of the issues discussed herein, contact your GBA-member geotechnical engineer. Do not rely on this report if your geotechnical engineer prepared it: Active engagement in GBA exposes geotechnical • for a different client; engineers to a wide array of risk-confrontation • for a different project or purpose; techniques that can be of genuine benefit for • for a different site(that may or may not include all or a portion of everyone involved with a construction project. the original site);or before important events occurred at the site or adjacent to it; e.g.,man-made events like construction or environmental Understand the Geotechnical-Engineering Services remediation,or natural events like floods,droughts,earthquakes, Provided for this Report or groundwater fluctuations. Geotechnical-engineering services typically include the planning, collection,interpretation,and analysis of exploratory data from Note,too,the reliability of a geotechnical-engineering report can widely spaced borings and/or test pits.Field data are combined be affected by the passage of time,because of factors like changed with results from laboratory tests of soil and rock samples obtained subsurface conditions;new or modified codes,standards,or from field exploration(if applicable),observations made during site regulations;or new techniques or tools.If you are the least bit uncertain reconnaissance,and historical information to form one or more models about the continued reliability of this report,contact your geotechnical of the expected subsurface conditions beneath the site.Local geology engineer before applying the recommendations in it.A minor amount and alterations of the site surface and subsurface by previous and of additional testing or analysis after the passage of time-if any is proposed construction are also important considerations.Geotechnical required at all-could prevent major problems. engineers apply their engineering training,experience,and judgment to adapt the requirements of the prospective project to the subsurface Read this Report in Full model(s). Estimates are made of the subsurface conditions that Costly problems have occurred because those relying on a geotechnical- will likely be exposed during construction as well as the expected engineering report did not read the report in its entirety.Do not rely on performance of foundations and other structures being planned and/or an executive summary.Do not read selective elements only.Read and affected by construction activities. refer to the report in full. The culmination of these geotechnical-engineering services is typically a You Need to Inform Your Geotechnical Engineer geotechnical-engineering report providing the data obtained,a discussion About Change of the subsurface model(s),the engineering and geologic engineering Your geotechnical engineer considered unique,project-specific factors assessments and analyses made,and the recommendations developed when developing the scope of study behind this report and developing to satisfy the given requirements of the project.These reports may be the confirmation-dependent recommendations the report conveys. titled investigations,explorations,studies,assessments,or evaluations. Typical changes that could erode the reliability of this report include Regardless of the title used,the geotechnical-engineering report is an those that affect: engineering interpretation of the subsurface conditions within the context - the site's size or shape; of the project and does not represent a close examination,systematic inquiry,or thorough investigation of all site and subsurface conditions. the elevation,configuration,location,orientation, function or weight of the proposed structure and Geotechnical-Engineering Services are Performed the desired performance criteria; the composition of the design team;or for Specific Purposes, Persons, and Projects, . project ownership. and At Specific Times Geotechnical engineers structure their services to meet the specific As a general rule,always inform your geotechnical engineer of project needs,goals,and risk management preferences of their clients.A or site changes-even minor ones-and request an assessment of their geotechnical-engineering study conducted for a given civil engineer impact.The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical conspicuously that you've included the material for information purposes engineer was not informed about developments the engineer otherwise only.To avoid misunderstanding,you may also want to note that would have considered. "informational purposes"means constructors have no right to rely on the interpretations,opinions,conclusions,or recommendations in the Most Of the "Findings" Related in This Report report.Be certain that constructors know they may learn about specific Are Professional Opinions project requirements,including options selected from the report,only Before construction begins,geotechnical engineers explore a site's from the design drawings and specifications.Remind constructors subsurface using various sampling and testing procedures.Geotechnical that they may perform their own studies if they want to,and be sure to engineers can observe actual subsurface conditions only at those specific allow enough time to permit them to do so.Only then might you be in locations where sampling and testing is performed.The data derived from a position to give constructors the information available to you,while that sampling and testing were reviewed by your geotechnical engineer, requiring them to at least share some of the financial responsibilities who then applied professional judgement to form opinions about stemming from unanticipated conditions.Conducting prebid and subsurface conditions throughout the site.Actual sitewide-subsurface preconstruction conferences can also be valuable in this respect. conditions may differ-maybe significantly-from those indicated in this report.Confront that risk by retaining your geotechnical engineer Read Responsibility Provisions Closely to serve on the design team through project completion to obtain Some client representatives,design professionals,and constructors do informed guidance quickly,whenever needed. not realize that geotechnical engineering is far less exact than other engineering disciplines.This happens in part because soil and rock on This Report's Recommendations Are project sites are typically heterogeneous and not manufactured materials Confirmation-Dependent with well-defined engineering properties like steel and concrete.That The recommendations included in this report-including any options or lack of understanding has nurtured unrealistic expectations that have alternatives-are confirmation-dependent.In other words,they are not resulted in disappointments,delays,cost overruns,claims,and disputes. final,because the geotechnical engineer who developed them relied heavily TO confront that risk,geotechnical engineers commonly include on judgement and opinion to do so.Your geotechnical engineer can finalize explanatory provisions in their reports.Sometimes labeled"limitations,' the recommendations only after observing actual subsurface conditions many of these provisions indicate where geotechnical engineers' exposed during construction.If through observation your geotechnical responsibilities begin and end,to help others recognize their own engineer confirms that the conditions assumed to exist actually do exist, responsibilities and risks.Read these provisions closely.Ask questions. the recommendations can be relied upon,assuming no other changes have Your geotechnical engineer should respond fully and frankly. occurred.The geotechnical engineer who prepared this report cannot assume responsibility or liabilityfor confirmation-dependent recommendations fyou Geoenvironmental Concerns Are Not Covered fail to retain that engineer to perform construction observation. The personnel,equipment,and techniques used to perform an environmental study-e.g.,a"phase-one"or"phase-two"enviromnental This Report Could Be Misinterpreted site assessment-differ significantly from those used to perform a Other design professionals'misinterpretation of geotechnical- geotechnical-engineering study.For that reason,a geotechnical-engineering engineering reports has resulted in costly problems.Confront that risk report does not usually provide environmental findings,conclusions,or by having your geotechnical engineer serve as a continuing member of recommendations;e.g.,about the likelihood of encountering underground the design team,to: storage tanks or regulated contaminants.Unanticipated subsurface • confer with other design-team members; environmental problems have led to project failures.If you have not • help develop specifications; obtained your own environmental information about the project site, review pertinent elements of other design professionals'plans and ask your geotechnical consultant for a recommendation on how to find specifications;and environmental risk-management guidance. • be available whenever geotechnical-engineering guidance is needed. Obtain Professional Assistance to Deal with You should also confront the risk of constructors misinterpreting this Moisture Infiltration and Mold report.Do so by retaining your geotechnical engineer to participate in While your geotechnical engineer may have addressed groundwater, prebid and preconstruction conferences and to perform construction- water infiltration,or similar issues in this report,the engineer's phase observations. services were not designed,conducted,or intended to prevent migration of moisture-including water vapor-from the soil Give Constructors a Complete Report and Guidance through building slabs and walls and into the building interior,where Some owners and design professionals mistakenly believe they can shift it can cause mold growth and material-performance deficiencies. unanticipated-subsurface-conditions liability to constructors by limiting Accordingly,proper implementation of the geotechnical engineer's the information they provide for bid preparation.To help prevent recommendations will not of itself be sufficient to prevent the costly,contentious problems this practice has caused,include the moisture infiltration.Confront the risk of moisture infiltration by complete geotechnical-engineering report,along with any attachments including building-envelope or mold specialists on the design team. or appendices,with your contract documents,but be certain to note Geotechnical engineers are not building-envelope or mold specialists. GEOPROFESSIONAL BUSINESS SEA ASSOCIATION Telephone:301/565-2733 e-mail:info@geoprofessional.org www.geoprofessional.org Copyright 2019 by Geoprofessional Business Association(GBA).Duplication,reproduction,or copying of this document,in whole or in part,by any means whatsoever,is strictly prohibited,except with GBAs specific written permission.Excerpting,quoting,or otherwise extracting wording from this document is permitted only with the express written permission of GBA,and only for purposes of scholarly research or book review.Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind. Any other firm,individual,or other entity that so uses this document without being a GBA member could be committing negligent or intentional(fraudulent)misrepresentation.