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HomeMy WebLinkAboutSDP200500125 Assessment - Groundwater 2006-06-06 WATER QUALITY ANALYSIS RECF..111ED JUN 0 6 2006 COMMUNITY DEVELOPMENT Modified Simple Method Worksheets Divide the Site into Drainage Areas— Worksheet 1 Calculate the area in acres for each drainage area, and label each drainage area on the plan. It will be necessary to fill out the following series of worksheets for each drainage area. Drainage Area l: 7 9b acres (on-site); !. 7Z acres (off-site); ‘. 6-9 total acres Drainage Area 2: 3.68 acres (on-site); — acres (off-site); 3.. 68 total acres Drainage Area 3: 2_3s acres (on-site); acres (off-site); 2. 33- total acres Drainage Area 4: 0. 3 acres(on-site); /• S acres (off-site); / 5' ' total acres Drainage Area 5: 3•q6 acres (on-site); acres (off-site); 3-96 total acres IA Drainage Area 0 3 acres(on-site); — acres (off-site); 0-3 total acres 2A Drainage Area 7: U. 3 acres(on-site); — acres (off-site); 0-3 total acres a2A 4 M CA = 0-67to/dsrrj — (or-s.Tr) a.67 rat Ac. r Total (On-site) Area= /6. S'I acres 05 February 2003 WR-8 Calculate Pre-Development Impervious Cover (I pre) - Worksheet 2 Calculate I(pre) using actual site information for each drainage area (on-site acres only) as identified in Worksheet 1. If the project is phased, include only the active phase(s). DRAINAGE AREA # I ON-SITE AREA = 7. S ACRES (on-site drainage area size) Roads: length (ft) x width (ft) for all roads . = square feet Driveways: average length (ft) x average width (ft) x number of driveways = square feet Parking Lots: square footage = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses . = square feet Actively-grazed pasture(livestock present), Yards & areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 = square feet Other Impervious Areas = square feet Total Equivalent Impervious Area = ?‘S2 square feet (sum of all the above values) I(pre) = Total Equivalent Impervious Cover(sq ft) x 100 = —7 % 43560 sq ft per acre/on-site drainage area(acs.) DRAINAGE AREA # 2 ON-SITE AREA = 3. 6`f ACRES (on-site drainage area size) Roads: length (ft) x width(ft) for all roads . = square feet Driveways: average length (ft) x average width (ft)x number of driveways = square feet Parking Lots: square footage = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses . = square feet Actively-grazed pasture(livestock present), Yards & areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 = square feet Other Impervious Areas = square feet Total Equivalent Impervious Area = 21# 7o8 square feet (sum of all the above values) I(pre) = Total Equivalent Impervious Cover(sq ft) x 100 = 1`i 43560 sq ft per acre/on-site drainage area(acs.) 05 February 2003 WR-8 Calculate Pre-Development Impervious Cover (I pre) - Worksheet 2 Calculate I(pre) using actual site information for each drainage area (on-site acres only) as identified in Worksheet 1. If the project is phased, include only the active phase(s). DRAINAGE AREA# 3 ON-SITE AREA = S. o6 ACRES (on-site drainage area size) Roads: length(ft) x width (ft) for all roads . = square feet Driveways: average length (ft) x average width (ft) x number of driveways = square feet Parking Lots: square footage . = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses . = square feet Actively-grazed pasture(livestock present), Yards & areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 . = square feet Other Impervious Areas . = square feet Total Equivalent Impervious Area = 17, COO square feet (sum of all the above values) I(pre) = Total Equivalent Impervious Cover(sq ft) x 100 = 9 % 43560 sq ft per acre/on-site drainage area(acs.) DRAINAGE AREA# / 4 ON-SITE AREA = 2.SO ACRES (on-site drainage area size) Roads: length (ft) x width (ft) for all roads . = square feet Driveways: average length (ft) x average width (ft) x number of driveways = square feet Parking Lots: square footage . = square feet Gravel Areas: square footage x 0.70 . = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses . = _ square feet Actively-grazed pasture(livestock present), Yards & areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 = square feet Active crop land: square footage x 0.25 . = square feet Other Impervious Areas . = square feet Total Equivalent Impervious Area = -- square feet (sum of all the above values) I(pre) = Total Equivalent Impervious Cover(sq ft) x 100 = U % 43560 sq ft per acre/on-site drainage area(acs.) 05 February 2003 WR-8 Calculate Pre-Development Impervious Cover (I pre) - Worksheet 2 Calculate I(pre) using actual site information for each drainage area (on-site acres only) as identified in Worksheet 1. If the project is phased, include only the active phase(s). DRAINAGE AREA# Z 4 ON-SITE AREA = 0-3v ACRES (on-site drainage area size) Roads: length(ft) x width(ft) for all roads . = square feet Driveways: average length (ft) x average width (ft)x number of driveways = square feet Parking Lots: square footage . = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses . = square feet Actively-grazed pasture (livestock present), Yards & areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 = square feet Active crop land: square footage x 0.25 . = square feet Other Impervious Areas . = square feet Total Equivalent Impervious Area = -- square feet (sum of all the above values) I(pre) = Total Equivalent Impervious Cover(sq ft) x 100 = C7 % 43560 sq ft per acre/on-site drainage area(acs.) DRAINAGE AREA# ON-SITE AREA = 0.67 ACRES (on-site drainage area size) Roads: length (ft) x width (ft) for all roads . = square feet Driveways: average length (ft) x average width (ft) x number of driveways = square feet Parking Lots: square footage = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses = square feet Actively-grazed pasture(livestock present), Yards & areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 = square feet Other Impervious Areas . = square feet Total Equivalent Impervious Area = 6,$d0 square feet (sum of all the above values) I(pre) = Total Equivalent Impervious Cover(sq ft) x 100 = 2 3 % 43560 sq ft per acre/on-site drainage area(acs.) 05 February 2003 WR-8 Calculate Pre-Development Phosphorus Load(Lpre) — Worksheet 3 Use the following table to calculate L(pre)based on the water resources area in which the project is located. Water Resources Area L(pre)= Development Area, where I(pre) is less than 1.41 x A or equal to 20% Development Area, where I(pre) is greater 6.14 x [0.05 + (0.009)(Ipre)] x A than 20% Water Supply Protection Area, no existing 0.15 x A impervious cover(do not count existing equivalent impervious cover from pasture or crop land) Water Supply Protection Area, site with 3.07 x [0.05 + (0.009)(Ipre)] x A existing impervious cover Other Rural Land,no existing impervious 0.21 x A cover(do not count existing equivalent impervious cover from pasture or crop land) Other Rural Land, site with existing 3.51 x [0.05 + (0.009)(Ipre)] x A impervious cover L(pre)= Pre-Development Phosphorus Load(pounds/year) I (pre) = Pre-Development Equivalent Impervious Cover (% expressed in whole numbers from Worksheet 2) A = On-Site Drainage Area(acres) DRAINAGE AREA# 2 ON-SITE AREA = 5 / ACRES (on-site drainage area size) L (pre) = /0-sy pounds per year(annual loading) 05 February 2003 WR-8 (Worksheet 3 — Continued) DRAINAGE AREA# 2- ON-SITE AREA = 3.'l6 ACRES (on-site drainage area size) L (pre)= es pounds per year(annual loading) DRAINAGE AREA# ON-SITE AREA = Li,3y ACRES (on-site drainage area size) L (pre) = 6./2. pounds per year(annual loading) DRAINAGE AREA# /4 ON-SITE AREA = O. 3 ACRES (on-site drainage area size) L (pre)= O•`i 2 pounds per year(annual loading) DRAINAGE AREA# Z f1 ON-SITE AREA = 0-3 ACRES (on-site drainage area size) L (pre) = 0.y2 pounds per year(annual loading) DRAINAGE AREA# 5A ON-SITE AREA = 0-67 ACRES (on-site drainage area size) L (pre) = 0-93— pounds per year(annual loading) DRAINAGE AREA# ON-SITE AREA = ACRES (on-site drainage area size) L (pre) = pounds per year(annual loading) 05 February 2003 WR-8 Calculate Post-Development Ultimate Impervious Cover (I post) - Worksheet 4 Use the following worksheet to calculate I(post) using assumed figures for build-out of the project, including roads, houses, driveways,yards, etc. DRAINAGE AREA# 1 ON-SITE AREA = v 96 ACRES (on-site drainage area size) Roads: length (ft) x width(ft) for all roads = square feet Driveways: average length(ft) x average width (ft) x number of driveways = square feet Parking Lots: square footage . . . . = square feet Gravel Areas: square footage x 0.70 . . = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses = square feet Actively-grazed pasture (livestock present), Yards & areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 . . . = square feet Other Impervious Areas . . . . . = square feet Total Equivalent Impervious Area = you/9z square feet (sum of all the above values) I(post) = Total Equivalent Impervious Cover(sq ft)x 100 = 4'2 % 43560 sq ft per acre/on-site drainage area(acs.) DRAINAGE AREA# 2 ON-SITE AREA = S.6$ ACRES (on-site drainage area size) Roads: length (ft) x width (ft) for all roads . = square feet Driveways: average length (ft) x average width (ft)x number of driveways = square feet Parking Lots: square footage . = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses = square feet Actively-grazed pasture (livestock present), Yards &areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 = square feet Other Impervious Areas . = square feet Total Equivalent Impervious Area = /09; 77,s square feet (sum of all the above values) I(post) = Total Equivalent Impervious Cover(sq ft)x 100 = 6'$ % 43560 sq ft per acre/on-site drainage area(acs.) 05 February 2003 WR-8 Calculate Post-Development Ultimate Impervious Cover (I post) - Worksheet 4 Use the following worksheet to calculate I(post) using assumed figures for build-out of the project, including roads, houses, driveways,yards, etc. DRAINAGE AREA# 3 ON-SITE AREA = 2.3s ACRES (on-site drainage area size) Roads: length(ft)x width (ft) for all roads . = square feet Driveways: average length (ft) x average width (ft)x number of driveways = square feet Parking Lots: square footage = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses . = square feet Actively-grazed pasture(livestock present), Yards &areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 = square feet Other Impervious Areas . = square feet Total Equivalent Impervious Area = /6, 6ZS square feet (sum of all the above values) I(post) = Total Equivalent Impervious Cover(sq ft) x 100 = iG % 43560 sq ft per acre/on-site drainage area(acs.) DRAINAGE AREA# y ON-SITE AREA = O.Sq ACRES (on-site drainage area size) Roads: length(ft)x width(ft) for all roads . . = square feet Driveways: average length(ft)x average width(ft)x number of driveways = square feet Parking Lots: square footage = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses . = square feet Actively-grazed pasture(livestock present),Yards &areas of cultivated turf actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 . . = square feet Other Impervious Areas . . = square feet Total Equivalent Impervious Area = — square feet (sum of all the above values) I(post) = Total Equivalent Impervious Cover(sq ft)x 100 = 0 % 43560 sq ft per acre/on-site drainage area(acs.) 05 February 2003 WR-8 Calculate Post-Development Ultimate Impervious Cover (I post) - Worksheet 4 Use the following worksheet to calculate I(post) using assumed figures for build-out of the project, including roads, houses, driveways,yards, etc. DRAINAGE AREA# S ON-SITE AREA = 3. 96 ACRES (on-site drainage area size) Roads: length(ft) x width (ft) for all roads . = square feet Driveways: average length (ft)x average width(ft)x number of driveways = square feet Parking Lots: square footage = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures,OR average house square footage x number of houses . = square feet Actively-grazed pasture (livestock present), Yards & areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 = square feet Other Impervious Areas = square feet Total Equivalent Impervious Area = /6, 2/0 square feet (sum of all the above values) I(post) = Total Equivalent Impervious Cover(sq ft)x 100 = 9 % 43560 sq ft per acre/on-site drainage area(acs.) DRAINAGE AREA# /A ON-SITE AREA = 0. 30 ACRES (on-site drainage area size) Roads: length(ft)x width(ft) for all roads . . = square feet Driveways: average length (ft) x average width (ft)x number of driveways = square feet Parking Lots: square footage = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures, OR average house square footage x number of houses . = square feet Actively-grazed pasture (livestock present), Yards &areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 = square feet Other Impervious Areas = square feet Total Equivalent Impervious Area = //,3 2 - square feet (sum of all the above values) I(post) = Total Equivalent Impervious Cover(sq ft)x 100 = 8 7 % 43560 sq ft per acre/on-site drainage area(acs.) 05 February 2003 WR-8 Calculate Post-Development Ultimate Impervious Cover (I post) - Worksheet 4 Use the following worksheet to calculate I(post) using assumed figures for build-out of the project, including roads, houses, driveways,yards, etc. DRAINAGE AREA# 2 A ON-SITE AREA = D-3 ACRES (on-site drainage area size) Roads: length(ft)x width(ft) for all roads . = square feet Driveways: average length (ft) x average width (ft)x number of driveways = square feet Parking Lots: square footage = square feet Gravel Areas: square footage x 0.70 = square feet Structures (including houses): sum of actual square footage for all structures,OR average house square footage x number of houses = square feet Actively-grazed pasture(livestock present), Yards &areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 = square feet Other Impervious Areas = square feet Total Equivalent Impervious Area = /0, y 6v square feet (sum of all the above values) I(post) = Total Equivalent Impervious Cover(sq ft)x 100 = 90 % 43560 sq ft per acre/on-site drainage area(acs.) DRAINAGE AREA# SA ON-SITE AREA = 0.67 ACRES (on-site drainage area size) Roads: length(ft) x width(ft) for all roads . = square feet Driveways: average length(ft) x average width(ft)x number of driveways = square feet Parking Lots: square footage = square feet Gravel Areas: square footage x 0.70 = square feet Structures(including houses): sum of actual square footage for all structures,OR average house square footage x number of houses . = square feet Actively-grazed pasture(livestock present), Yards & areas of cultivated turf: actual square footage of areas x 0.08, OR average yard area x number of yards x 0.08 . = square feet Active crop land: square footage x 0.25 . . = square feet Other Impervious Areas . = square feet Total Equivalent Impervious Area = /3,vop square feet (sum of all the above values) I(post) = Total Equivalent Impervious Cover(sq ft)x 100 = £fS % 43560 sq ft per acre/on-site drainage area(acs.) 05 February 2003 WR-8 Calculate Post-Development Phosphorus Load(L post) — Worksheet 5 Use the following table to calculate L(post) based on the water resources area in which the project is located. Water Resources Area L(post)= Development Area 6.14 x [0.05 +(0.009)(Ipost)] x A Water Supply Protection Area 3.07 x [0.05 + (0.009)(Ipost)] x A Other Rural Land 3.51 x [0.05 +(0.009)(Ipost)] x A L(post) = Post-Development Phosphorus Load(pounds/year) I (post) = Post-Development Equivalent Impervious Cover (% expressed in whole numbers from Worksheet 4) A = On-Site Drainage Area(acres) DRAINAGE AREA# 1 ON-SITE AREA = z} 9t ACRES (on-site drainage area size) L (post) = 13-0 3 pounds per year(annual loading) DRAINAGE AREA# 2- ON-SITE AREA = 3-6$ ACRES (on-site drainage area size) L (post)= /474, 96 pounds per year(annual loading) DRAINAGE AREA# ON-SITE AREA = 2 . 3 S ACRES (on-site drainage area size) L (post) = 2-43 O pounds per year(annual loading) 05 February 2003 WR-8 (Worksheet 5— Continued) DRAINAGE AREA# �} ON-SITE AREA = (7-3'1 ACRES (on-site drainage area size) L (post) = '/D pounds per year(annual loading) DRAINAGE AREA# ON-SITE AREA = 3.96 ACRES (on-site drainage area size) L (post) = 3. /9 pounds per year(annual loading) DRAINAGE AREA# /A ON-SITE AREA = O- 3 ACRES (on-site drainage area size) L (post) = /- 5-3 pounds per year(annual loading) DRAINAGE AREA# Z A ON-SITE AREA = ©-' ACRES (on-site drainage area size) L (post) = j- 4f Z pounds per year(annual loading) DRAINAGE AREA# S'4 ON-SITE AREA = 0.6 7 ACRES (on-site drainage area size) L (post)= I. e 7 pounds per year(annual loading) 05 February 2003 WR-8 Calculate Pollutant Removal Requirement— Worksheet 6 RR = (Pollutant) Removal Requirement= L post—( L pre x f) (pounds per year) Where "f' is a factor applied to the Removal Requirement based upon the Conditions described below. %RR= Overall BMP Pollutant Removal Efficiency= ( RR x 100 )/L post (percent) Condition 1 — "No Existing Impervious Cover" ; f= 1.0 This condition does not include equivalent impervious cover from pasture/crop land. It includes"new development" in all water resources areas and"adding impervious cover to existing sites"when existing impervious cover is within: • Development Area and is less than or equal to 20% • Water Supply Protection Area and is 0% • Other Rural Land and is less than or equal to 1% Condition 2 —"Adding Impervious Cover To Sites With Existing Impervious Cover"in the Development Areas ; f= 0.90 This condition includes"adding impervious cover to existing sites"when existing impervious cover is greater than 20% or is designated as "infill and redevelopment". Condition 3— "Adding Impervious Cover To Sites With Existing Impervious Cover" in the Water Supply Protection Area or Other Rural Land ; f= 0.85 This condition includes "adding impervious cover to existing sites"when existing impervious cover is within: • Water Supply Protection Area and is greater than 0% • Other Rural Land and is greater than 1% • Designated as "infill and redevelopment" DRAINAGE AREA #/,2,3 4`/ Condition: ❑ 1 ❑ 2 ❑ 3 Lpost= 30.Sq Lpre= /5.'17 RR= /S.'/2. %RR= `H.1 05 February 2003 WR-8 (Worksheet 6— Continued) DRAINAGE AREA # S Condition: ❑ 1 ❑ 2 ❑ 3 L post= I. ?7 L pre = RR = %RR= % DRAINAGE AREA # / 4 Condition: ❑ 1 ❑ 2 ❑ 3 L post= 1. 53 L pre = G-l/Z RR= /. // %RR= '73 % DRAINAGE AREA # 2/4 Condition: 0 1 ❑ 2 ❑ 3 L post= I. `/Z L pre= 0-`/2 RR= /, v %RR= —X) % DRAINAGE AREA# 57 Condition: ❑ 1 ❑ 2 ❑ 3 L post= /. 0 7 L pre= ©,"S RR= O. 92 %RR= St) % DRAINAGE AREA# Condition: ❑ 1 ❑ 2 0 3 L post= L pre= RR= %RR= % DRAINAGE AREA# Condition: ❑ 1 0 2 ❑ 3 Lpost= Lpre = RR= %RR= % DRAINAGE AREA # Condition: ❑ 1 ❑ 2 ❑ 3 L post= L pre = RR= %RR= % 05 February 2003 WR-8 $TbA. w.M, ,Z Mo/)'L DIA6fl4,A • Posr DE.0E47? r gov:I.J 3. 15 Ac. C 3. b S AL o.3 Ac.) A4. 02 + bA. w2A Date cn Area 2 • Slam sawer.2 '"L10 a c57/2 62 DA.403 akar 2 3S AC o d fl w tm,�l,outran J , ttQ. It° Lie Rd*,niAid AIM Slam Sewem Dated*Area 1 -„cam 044 • 6. 9gA ( a4r.. * o3Ac f A.A, �►1 * l Ass14