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Home My WebLink AboutWPO201500068 Calculations 2015-09-11 HOLLYMEAD TOWN CENTER STORMWATER MANAGEMENT CALCULATIONS PACKET Date of Calculations AUGUST 3, 2015 Revised on SEPTEMBER 11, 2015 PREPARED BY: COLLI N SHSO G 1 N FEE 200 GARRETT STREET, SUITE K CHARLOTTESVILLE,VA 22902 434.293.3719 PH 434.293.2813 FX www.collins-engineering.com SCS TR-55 Calculations U.S.Department of Agriculture FL-ENG-21A Natural Resources Conservation Service 06/04 TR 55 Worksheet 2:Runoff Curve Number and Runoff Project: WPO Plan for SWM Facility#1(SB conversion) Designed By: FGM,PE Date: 9/10/2015 Location: Hollymead Town Center Checked By: SRC,PE Date: 9/10/201E Check One: Present X Dev X 1.Runoff curve Number(CN) Cover description Drainage Soil name and CN(weighted)= (Cover type,treatment,and hydrologic condition; Area Product of Calculated Area hydrologic group percent impervious;unconnected/connected CN (Acres) CN x Area total product/ 'S'Value Description (Appendix A) total area impervious area ratio) DA A Impervious Areas(Dickerson Dr+Willow Glen) • 98 0.63 61.9 B Woods in Good Condition(Remainder of watershed) 55 12.31 677.0 57.1 7.51 (Present) Lawns in Good Condition 61 0.00 0.0 DA A Impervious Areas(Exist+Future Dev+Towncenter Dr) 98 7.25 710.8 (Developed) B Woods in Good Condition 55 0.00 0.0 81.7 2.23 Lawns in Good Condition 61 5.69 346.9 2.Runoff 1-Year Storm 2-Year Storm Drainage Area Description Frequency-years 1 2 n/a Rainfall,P(24 hour)-inches 3.5 3.7 n/a - Runoff,Q-inches 0.42 0.50 DA A(Present) Runoff,Q-inches 1.76 1.93 DA A(Developed) Runoff,Q-inches Runoff,Q-inches U.S.Department of Agriculture FL-ENG-21A Natural Resources Conservation Service 06/04 TR 55 Worksheet 3:Time of Concentration(T c)or Travel Time(Tx) Project: WPO Plan for SWM Facility#1(SB conversion) Designed By: FGM,PE Date: 8/3/2015 Location: Hollymead Town Center Checked By: SRC,PE Date: 8/3/2015 Check One: Present X Developed X Check One: Tc X Tt Through subarea n/a DAA DA A Segment ID: (Present) (Developed) Sheet Flow:(Applicable to Tc only) 1 Surface description(Table 3-1) Dense Grasses Dense Grasses 2 Manning's roughness coeff.,n(Table 3-1 0.24 0.24 3 Flow length,L(total L<100)(ft) 100 100 4 Two-year24-hour rainfall,P2(in.) 3.7 3.7 5 Land slope,s(ft/ft) 0.02 0.02 6 Compute Tt=[0.007(n*L)o.8]/p20.5 2.5 s0.4 0.22 0.22 Shallow Concentrated Flow: 7 Surface description(paved or unpaved) unpaved 8 Flow Length,L(ft) 1170 9 Watercourse slope,s(ft/ft) 0.06 10 Average velocity,V(Figure 3-1)(ft/s) 4.0 Estimated 11 Tt=L/3600*V 0.08 0.03 Channel Flow: 12 Cross sectional flow area,a(ft 2) 13 Wetted perimeter,PW(ft) 14 Hydraulic radius,r=a/PW(ft) 15 Channel Slope,s(ft/ft) 16 Manning's Roughness Coeff,n 17 V=[1.49r213s°5]/n 18 Flow length,L(ft) 19 Tt=L/3600*V 20 Watershed or subarea TcorTt (Add Tt in steps 6,11 and 19) 0.30 0.25 U.S. Department of Agriculture FL-ENG-21C Natural Resources Conservation Service 06/04 TR 55 Worksheet 4:Graphical Peak Discharge Method Project: WPO Plan for SWM Facility#1(SB conversion) Designed By: FGM, PE Date: 9/10/2015 Location: Hollymead Town Center Checked By: SRC, PE Date: 9/10/2015 Check One: Present X Developed X Drainage Area Drainage Area Drainage Area Drainage Area 1. Data Description Description Description Description DAA DA A (Present) (Developed) Drainage Area (Am)in miles2= 0.0202 0.0202 Runoff curve number CN= 57 82 Time of concentration (Tc)= 0.30 0.25 Rainfall distribution type= II II Pond and swamp areas spread 0 0 throughout the watershed= 2. Frequency-years 1 2 1 2 3. Rainfall, P(24 hour)-inches 3.50 3.7 3.50 3.7 4. Initial Abstraction, la-inches 1.503 1.503 0.447 0.447 • 5.Compute la/P 0.43 0.41 0.13 0.12 6. Unit peak discharge,Qu-csm/in 425 450 700 700 7. Runoff, Q from Worksheet 2-inches 0.42 0.50 1.76 1.93 8. Pond and Swamp adjustment factor, Fp 1 1 1 1 9. Peak Discharge,Qp-cfs Routed Through where Qp=Qu Am Q Fp 3.60 4.52 SWM Facility Watershed Summary Pre-Development Future Post-Development Area 1-Year Outfall 2-Year Outfall Area 1-Year Outfall 2-Year Outfall Description (acres) CN (cfs) (cfs) (acres) CN (cfs) (cfs) DA A 12.94 57.1 3.60 4.52 12.94 81.7 0.67 1.56 11, Post-Development Routings & Channel Protection Calculations 1` f HTC Sediment Basin Conversion- SWM Facility No. 1 UPDATED RISER BasinFlow printout INPUT: Basin: HTC Sediment Basin Conversion- SWM Facility No. 1- UPDATED RISER 6 Contour Areas Elevation(ft) Area(sf) Computed Vol . (cy) 521.00 19560.00 0.0 522.00 21655.00 762.9 523.00 23703.00 1602.6 524.00 25839.00 2519.7 525.00 27775.00 3512.4 526.00 30136.00 4584.5 Start_Elevation(ft) 521.00 Vol . (cy) 0.00 5 Outlet Structures Outlet structure 0 Orifice name: Proposed Barrel area (sf) 1.227 diameter or depth (in) 15.000 width for rect. (in) 0.000 coefficient 0.500 invert (ft) 518.000 multiple 1 discharge out of riser Outlet structure 1 Orifice name: Low Flow orifice area (sf) 0.049 diameter or depth (in) 3.000 width for rect. (in) 0.000 coefficient 0.500 invert (ft) 521.000 multiple 1 discharge into riser Outlet structure 2 Orifice name: Mid Flow Orifice area (sf) 0.049 diameter or depth (in) 3.000 width for rect. (in) 0.000 coefficient 0. 500 invert (ft) 522.600 multiple 1 discharge into riser Outlet structure 3 Weir name: Proposed Riser diameter (in) 24.000 side angle 0.000 coefficient 3.300 invert (ft) 523.600 multiple 1 discharge into riser transition at (ft) 0.608 orifice coef. 0.500 orifice' area (sf) 3.142 Page 1 , i i 1 HTC Sediment Basin Conversion- SWM Facility No. 1 UPDATED RISER Outlet structure 4 Weir name: Proposed Emergency Spillway length (ft) 90.000 side angle 71.565 coefficient 3.300 invert (ft) 524.600 multiple 1 discharge through dam 4 Inflow Hydrographs Hydrograph 0 SCS name: 1-yr 24-hr Peak SCS TR-55 Method Storm Event Area (acres) 12.940 CN 81.700 Type 2 rainfall , P (in) 3.500 time of conc. (hrs) 0.2500 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 23.153 peak time (hrs) 12.003 volume (cy) 3058.579 Hydrograph 1 SCS name: 2-yr 24-hr Peak SCS TR-55 Method Storm Event Area (acres) 12.940 CN 81.700 Type 2 rainfall , P (in) 3.700 time of conc. (hrs) 0.2500 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 25.330 peak time (hrs) 12.003 volume (cy) 3346.101 Hydrograph 2 SCS name: 10-yr 24-hr Peak SCS TR-55 Method Storm Event Area (acres) 12.940 CN 81.700 Type 2 rainfall , P (in) 5.600 time of conc. (hrs) 0.2500 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 47.233 peak time (hrs) 12.003 volume (cy) 6239.581 Page 2 HTC Sediment Basin Conversion- SWM Facility No. 1 UPDATED RISER Hydrograph 3 SCS name: 100-yr 24-hr Peak SCS TR-55 Method Storm Event Area (acres) 12.940 CN 81.700 Type 2 rainfall , P (in) 9.100 time of conc. (hrs) 0.2500 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 90.402 peak time (hrs) 12.003 volume (cy) 11942.307 OUTPUT: Routing Method: storage-indication Hydrograph 0 Routing Summary of Peaks: 1-yr 24-hr Peak SCS TR-55 Method Storm Event inflow (cfs) 23.125 at 12.00 (hrs) discharge (cfs) 0.671 at 13.96 (hrs) water level (ft) 523.641 at 13.96 (hrs) storage (cy) 2181.109 Hydrograph 1 Routing summary of Peaks: 2-yr 24-hr Peak SCS TR-55 Method Storm Event inflow (cfs) 25.299 at 12.00 (hrs) discharge (cfs) 1.555 at 13.08 (hrs) water level (ft) 523.736 at 13.10 (hrs) storage (cy) 2269.863 Hydrograph 2 Routing Summary of Peaks: 10-yr 24-hr Peak SCS TR-55 Method Storm Event inflow (cfs) 47.175 at 12.00 (hrs) discharge (cfs) 25.572 at 12.16 (hrs) water level (ft) 524.727 at 12.16 (hrs) storage (cy) 3233.797 Hydrograph 3 Routing Summary of Peaks: 100-yr 24-hr Peak SCS TR-55 Method Storm Event inflow (cfs) 90.291 at 12.00 (hrs) discharge (cfs) 87.732 at 12.02 (hrs) water level (ft) 524.998 at 12.02 (hrs) storage (cy) 3510.121 Thu Sep 10 10:38:51 EDT 2015 Page 3 .t.xspa.,/t4cL, tLSI•tALL.'t' r4C.t„Zit,“.4t1 -C1 C.,10-N C.- ANJC-4, 69 tvc ot.)s) effl C.IC: -It 1.4 e"4. SIA'43'1 44N4 '' ii Ws1 tAP,tN. 4,N%,•-.140:: Cw\JVC:MMIC.C. .S.,t.S\Vo\A!,,, tp\i'.E.N) TIk'Pm 44.? r,,?•}1, tc•S tL M oy,) Vilivve 0,0m "i 09e°. CAM., - Hot*, ,tA-A4f4i-k ,Attt,:t+.; \ot,,A ALpLA‘lt 0" r:2 , (7,1 „,1 • `i• Cmp1/2)timi,m1') • 0,'"g > , ati... k:.ia 4 C. E. Di, (6.-g)/ 3.60 toLm v.bp..y:.7;1- OiNizAw:A) - • 1: PA, 1.4 r), GIS 3 •atic:'4,1Pri \-‘2 al :04 c4J.,„.0 V•tz- .4 VCR t.41c4•44 c'Avs‘ , t: 0, • "t • • • • 1999 Grandfathered VSMH Calculations PERFORMANCE-BASED WATER QUALITY CALCULATIONS APPENDIX SD 11111 Worksheet I Page 1 of 3 STEP 1 Determine the applicable area(A)and the post-developed impervious cover aims). Applicable area(A)* = 13,A acres ODkPl-z4p,,,6•F.;.. f A, 4 e".:4-- Post-developmpnt impervious cover: stfustlifee = •--..46t.W?:;,aeres„ , Vgitok-4 43-afking-lot (;d21,0aC1, acres Atfi=, feadway = .a,ores other: ').4t it5iNJ= klo eery ; acres • Total = acres 'post=(total post-development impervious cover A) x 100= The area subject to the criteria may vary from locality to locality. Therefore, consult the locality for proper determination of this value. STEP 2 Determine the average land cover condition('watered)or the existing impervious cover(Iexming). Average land cover condition(1,3tersh : If the locality has determined land cover conditions for individual watersheds within its jurisdiction, use the watershed specific value determined by the locality as L. —watershed. lwatershed Otherwise,use the Chesapeake Bay default value: Twatashed =:16% 5D-5 PERFORMANCE-BAS.. D WATER QUALITY CALCULATION APPENDIX 5D Worksheet 1 Page 2 of 3 Existing impervious cover{Iexistrigl• Determine the existing impervious cover of the development site ifpresent. Existing impervious cover: Via r stryletur s _ ?o t ur4es+" •p4ugb4et = � ' t a •`� roadway = acres other: acres = acres Total = 0.63 acres Ie ting=(total existing impervious cover_A*) x 100= 4.\j * The area should.be,the same as used in STEP 1, STEP 3 Determine the appropriate development.situation: The site information determined in STEP 1. and STEP 2 provide enough information to determine the appropriate development situation under which the performance criteria will apply. Check.(• )the.appropriate development situation as.follows: Situation 1: This consists of land development where the existing percent imperious cover(Iedatig)is less than or equal to the average land cover condition ("watershed and the proposed improvements will create a total percent impervious cover(Ip„,.)which is less than or equal to the average land cover condition(Iwaterrshed). • Ipost o/O• (watershed 5D-6 r • PERFORMANCE-BASEDf WATER QUALITY CALCULATIONS .. APPENDIX 5D Worksheet 1 Page 3 of 3' V Situation 2: This consists of land:development where the existing percent-impervious cover"(Ie, ,;„g)is less than or equal to the average land cover condition Uwatershed)and the proposed improvements will create a total.percent impervious cover(li,os)which is greater than the average land cover condition(Iyya shed). 'existing, 4'CI % ''watershed 1G %;and 'post "' >'watershed '6 % Situation 3; This.consists ofland development Where the existing percent.impervious cover(Ie i;;t)is greater than the average"land,cover condition.(Iwatershea). 'existing %.'watershed , Situation 4: This consists of land development where.the existing percent impervious Over(Lung)is served by an existing stormzvater management BMP(s) that addresses water quality. If the.proposed development meets the criteria for development Situation 1.,than the low density development is considered to be the BMP and no pollutant removal is required. The calculation procedure for Situation 1 stops here. If the proposed development meets the criteria for development Situations 2,3,or 4,then proceed to STEP 4 On the appropriate worksheet. 5D-7 • PERFORMANCE-BASED WATER QUALITY CALCULATIONS 'APPENDIX SD • Worksheet 2: Situation 2 Page 1 of 4 Summary of Situation 2 criteria: from calculation procedure STEP 1,thru STEP 3,,Worksheet 1 Applicable area(A)* M,` a1 acres Ip„t =(total post-deg elopment impervious cover_A) x 100 5.6 O % `watershed % or 'watershed = 16% =(total existing impervious cover=A.*) x 100 L(St % lodoing "'Watershed. (*, %;,and 'post -� ti r4.' %>'watershed 16 % STEP 4 Determine the relative pre-development pollutant load (Lp, ), 1'pre(watershed)=[0.05 +(0.009 x Iwatershed)] x A x 2.28 (Equation'5-1.6) where: Lpre(watershed) = relative pre-development total phosphorous load (pounds per year) 'watershed average land cover condition for specific watershed or locality or the Chesapeake Bay default value of 16%(percent expressed in. whole numbers) A = applicable area(acres) Lpre(watershed)=[0.05 +(0.009 x 16 )] x oa;r'+,=i x 2.28 = 5,1 R pounds per year 5D-9 • • PERFORMANCE-BASED WATER QUALITY CAI,CULATIONS APPENDIX 5D Worksheet 2: Situation 2 Page 2 of 4 STEP 5 Determine the relative post4levelOpment pollutant load(L .). Lpost = [0.05+(0.009 x 11,0 )1 x A x 2.28 (Equation 5-21) where: Lpost = relative post-development total Phosphorous load(pounds per year) Ipa,„ = post-development percent impervious cover(percent expressed in 'whole numbers) A = applicable area(acres) Lpos, = [0.05+(0.009 x. 56.0 )1 x • IR x 2,28 = I6.344, pounds per year STEP 6 Determine,the relative pollutant removal requirement(RR). RR ',post ••'•Lpre(WaterShed) RR • = ca, pounds per year STEP 7 Identify best management practice:(BMP)for the site. 1. Determine the required pollutant removal efficiency for the site: EFF = (.RR 4. x Joo (Equation 5-22) where; EFF' required pollutant removal efficiency (percent expressed in whole. numbers) RR = pollutant removal requirement(pound..5 per year) Lp„,t = relative post-development total phosphorous load(pounds per year) EFF = ( tO,6P4 ) x 100 % 5D-10 • , PERFORMANCE-BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet2: Situation 2 Page 3 of 4 2. Select BMP(s)from Table 5-15 and locate on the site: BMP 1: RE-1&-)10r.,1 F.jiA 6443r. ‘173: 1 BMP 2: BMP 3: 3. Determine the pollutant load entering the proposed BMP(s) Limp = [0.05+(O.009'g fBmp)] x A x (Equation 5-23) where: := relative post-development-total phosphorous load entering proposed BMP(pounds per year) 1/3mti = post-development percent impervious cover of BMP drainage area (percent expressed in whole numbers) A = drainage area of proposed BMP(acres) LBmpi = [0.05+ (0.009 x 56.0 x x 2.28 =. t g.3 LI pounds per year LBmp2 = [0.05 + (0.009 x )J x x 2.28 pounds per year Ismpl = [0.05+ (0,0.09 < )] x x 2.28 pounds per year 5D-11 PERFORMANCE-BASED-WATER QUALITY CALCULATIONS : APPENDIX 5D Worksheet 2: Situation 2 Page 4 of 4 • 4. Calculate the pollutant load removed by the proposed BMP(s):: Lremoved: = EffBMP x LBMP (Equation 544) where! 1.„..noved! .--= Post-development pollutant load removed:by proposed BMP (pounds per year) .EffBmp = pollutant removal efficiency Of BMP(expressed iii decimal form), LB mp --= relative post-development total phosphorous load entering proposed BMP(pounds per year). Lremoveil/B1VLIP1 =. 0.,4 5 le,7,3L1 = 0,6a potthde per year liremoved/BMP2 x = pounds per year = x = pounds,per year Lremoved/BMP3 = _ 5, Calculate the total pollutant load removed by the BMP(s): Lrcmoved/total = Liemoved/BT1+LrememedIBMP2±Lttniovedals/23+- . .(Equation$-25) where: Lreovemotai =total pollutant load,removed by proposed BMPs LrembvediBVPI =pollutant load retrieved by proposed BMP No. 1, Lremoved/f§MP2=pollutant load removed by proposed BMP No. 2 LiwnovediBmp3=pollutaiyt load removed by proposed"BMP No. 3 Lremoved/total — 1 C:4,G;L + iv/A" + 'ibel = pounds'per year 7 6. Verify compliance; Lremoved/total BR Mia, ;=• \O,61.a 5D-12 COLLINS .IARRETT ST, SUITE K CHARLOTTESVILLE VA 22902 ..._ 434.293.3719 PH 434.293.2813 FX www.collins-engineering.com Glenn Brooks, P.E. Community Development County of Albemarle 401 McIntire Road, Room 227 Charlottesville,VA 22902 RE: Hollymead Town Center SWM Plan(WPO 201300067) Thank you for your comments on the project referenced above. Please let this letter supplement the revised plans in response to your comments dated November 21,2013. Stormwater Management Plan 1. An asbuilt survey of the sediment basin has been incorporated with the survey and the topography shown.As asbuilt survey was conducted by Lincoln Surveying in June and August of 2015.The volumes and structures are accurate to the best of the applicant's knowledge.The existing riser and barrel are proposed to remain,with modifications to the existing riser to accept a proposed riser and barrel.An additional modification to the existing riser is also proposed.This modification is to include the sealing of all of its openings.This configuration was deemed acceptable in a meeting held on August 28th,2015 with County Engineering,hereby addressing this comment. 2. The plan has been revised such that the proposed slopes upland of the mean water surface elevation are now 3:1, not 2:1 as previously shown.The plan also incorporates a 10'wide,shallow aquatic bench.The bench also does not maximize the allowable 18"depth and only proposes a depth of 12"when the water level is full without the presence of evaporation and infiltration. This safety bench provides a barrier between the side slopes and the'deeper' portions of the pond,which has a maximum depth of only 5'. This too does not maximize the total allowable depth of 6'. If absolutely required,the applicant can also incorporate a fence encompassing the facility. It is the applicant's hope that these revisions will suffice without the need for a fence. Also,this facility is atypical because it wasn't designed for its upland watershed per say, rather it was designed to conform to the existing conditions and its future upland watershed will be restricted based of what this facility can naturally provide/service.This is evident in the minimal grading impacts proposed,the preservation of the existing riser and barrel consistent with County Engineering's desire and the introduction of fill with very limited cut in an area prone to rock outcroppings and fissures.The applicant believes the proposed plan is the ideal configuration for a challenging site and the plan no longer proposes a difficult construction activity simply for the purposes of maximizing the space and volume. Rather the plan now proposes a construction friendly design that is realistic,and the future impervious area credit was back calculated for what the facility can provide. 3. The plans and calculations have been revised for the pre-development state such that the area reserved for the future development and Town Center Drive are analyzed as woods in good condition.There are minor impervious areas within the subarea from Willow Glen and Dickerson Road that exist in the pre- development state for this development, however these areas have a nominal impact on the overall weighted CN value for this watershed,which is calculated to be 57.1. 4. When the Hollymead Town Center zoning amendment was originally approved the receiving stream did not have a WPO buffer associated with it.There also wasn't a WPO buffer when this facility was constructed,as shown on the approved SUB2006-00113 for Town Center Drive. Because when the construction of the existing facility as it exists today was completed when there wasn't a WPO buffer for this stream,the applicant does not feel prior impacts within the current WPO buffer requires mitigation. In other words,the prior impacts were not impacts when the construction activity occurred.The applicant does however concede that proposed disturbed areas with this set of plans,which are located within the now current WPO buffer,should be mitigated.As such,the proposed plan shows these impacts and proposes mitigation for the proposed distrubances. 5. The calculations submitted show channel protection compliance in accordance with 9 VAC 25-870-66. 6. A. The proposed facility has been reconfigured such that runoff is no longer short-circuited with the outlet and inlet adjacent to each other.A proposed riser and barrel configuration has been added to the plans that is consistent with conversations held during the aforementioned August 28,2015 meeting. B. In this scenario,due to the presence of a high water table and rock beneath the surface,placing a spillway at natural grade,i.e.at the grade of the adjacent stream's banks,is not realistic.The applicant therefore located the emergency spillway slope in the most logical place given the topography,at the point along the embankment furthest upstream. The applicant also is mandating the contractor armor any proposed and existing disturbed slopes that are not stabilized with EC-2 matting.Such armoring includes the emergency,spillway. C. The plans have been revised to no longer lower SWM facility#1 with the exception of minor cut (12"+/-)in a small area of the facility.The applicant agrees with County Engineering and has revised the plan such that the basin is now designed to the most logical footprint for the site.The plan now shows the existing rock outcroppings to remain and accounts for their losses in the facility's volume.The plan now also shows predominantly fill grading operations and no longer proposes large amounts of cut. D. The plan has been revised and the lowest invert for the proposed riser is below the mean water surface elevation,and above the existing receiving riser/barrel.Similarly,the proposed riser's lowest orifice opening is located at the mean water surface elevation.And lastly,the plans have been revised to detail a concrete foundation,hereby addressing this comment. E. Per this comment,the subarea has been revised to include portions of the Willow Glen development that drain to the facility. F. The plans have been revised such that the peak 10-year storm event's water surface elevation is now only 13"above the riser's rim.Thus,the 10-year storm event is almost exclusively drained through the two 3"orifice openings until this minimal (peak)13" backwater occurs. Please note,this scenario is for the 10-year design storm and the 1-year design storm is completly detained with runoff exiting only through the two 3"orifice openings. Similarly,during the 2-year design storm the(peak)water surface elevation is only 1.5"above the riser rim. Please see the attached Stormwater Management Calculations Packet,inclusive of the channel protection compliance calculations,for additional information.The applicant believes this plan satisfies minimum requirements. 7. This comment is no longer applicable with the removal of SWM Facility#2. 8. This comment is no longer applicable with the removal of SWM Facility#3. If you have any questions regarding the proposed plans please do not hesitate to contact me. Sincerely, Graham Murray, PE