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HomeMy WebLinkAboutEDB Stormwater Harvesting Summary EXECUTIVE SUMMARY AGENDA ITEM: Jacobs Engineering Report on the Stormwater Harvesting Pilot Project: Study Objectives,Results and Conclusions. Project No. 3019-002 Date: April 12, 2023 BACKGROUND: CCUA has been interested in and exploring stormwater harvesting as a method of augmenting the reclaimed water system in future years when reclaimed water will become limited in supply. One element of this exploration was the commissioning of a Stormwater Harvesting Pilot Project to measure the quality and quantity of recoverable water from a typical stormwater pond next to the First Coast Outer Beltway (State Road 23). The project is a cost share funding project with the St. Johns River Water Management District. The facility was designed by Mittauer and Associates and constructed by Williams Construction. (a Construction was completed in April 2021, and Jacobs Engineering(Jacobs)was engaged by staff cto provide planning and testing services as well as recommendations following the study. The 0- field study was conducted from August 2021 through September 2022 to capture a full year's ca o hydrologic cycle. Jacobs will report today on the objectives, test results, and conclusions of the E study regarding the quantity and quality of the water from this type of pond to serve as a a supplemental reclaimed water source. Jacobs final report will allow CCUA to make long-term cc decisions for use of the stormwater harvesting concept to supplement CCUA's reclaimed water supply. ATTACHMENTS: PowerPoint Slides //PS(Author) //AA(Review) //PS(Final) Jacobs Reinven Challengiting ng tom today. orrow. Stormwater HarvestingProjectPilot Study Objectives, Results, and Conclusions April 18, 2023 Mike Dykes, P.E. — Principal In Charge Larry Gunn, P.E. — Project Manager Greg Brubaker, P.E. — Senior Technical Consultant Background and Objectives The Innovative Stormwater Harvesting Pilot Project was a collaborative effort between the Clay County Utility Authority and the St. Johns River Water Management District Stormwater • SJRWMD cost-share project "y arvesting mm 1 . - tif el 1! ,, .N • Key Milestones %, i $.4 �� ti 4 > i — Feasibility Studies: December 2014 CCUA andoin '1 ,1 2018 Mittauer & Associates. 41:_:1T: 4 1 j"-- 'S 7 v, , - - — Permitting, Design and Construction: Mittauer '' , :, ,1,,, l & Associates and Williams Construction 1 ~-� �� �_ o — Ribbon-cutting Ceremony: February 18, 2021 r,:4 mow mlir — Test Plan Development: Summer 2021 , �. ' ® Prithf',1111111i., p cc!, Jacobs . Apr •�. February18, 2021 • — Data Collection: August 2021—September to - - Ribbon-Cutting Ceremony . 2022, CCUA and Jacobs @@UA -# 6 SINCERE THANK YOU TO THE AUTHORITY, SJRWMD, AND ALL THOSE WHO HAVE BEEN INSTRUMENTAL IN DELIVERING THIS INNOVATIVE PROJECT ! Old J nninw 'oa.a* 3 Study objectives focused on real-world performance of the proposed Stormwater Harvesting System Concept ■ Develop a better understanding of operational characteristics. ■ Test the water quality and water quantity of harvested stormwater to determine if it can reasonably and economically be used as a supplemental water source for the reclaimed water system. to 4 ©Jacobs 2023 Testing Plan Overview Stormwater Harvesting Pilot Facility and Monitoring Locations 1' Outlet Control • Continuous Water Levels Structure \„ 6"Discharge FM to .: . , Existing : — 6 Temporary Observation Wells (TOWs) Stormwater System Outlet Pond 6B .f Manholes P•' — 2 Horizontal Well Cleanouts (COs) Tow-5 :To A '6 � ., — Pond 6A Stilling Well (SW- 1 ) _.- � =* • Daily and Periodic Water Levels •r -., �. _ ,mow.. _ ,4--41, T '' °,_ `� '' Pond 6B Outlet Control Structure n r --., Stormwater �- ,� ' ,.bw t� TOWs 1 through 6, Periodic Manual L Pond 6A ,- � , r � �. — g TOW-3 TOW-4 • Water Sampling Points i SW-1 CO-2 — Wet Well Discharge (PD- 1 ) to - i — Background (TOW- 1 ) M• t 11 _ s low-1 TOW-2 ` I ` M ' `! iy c0 1 6 ©Jacobs 2023 The Water Quality Sampling Plan evaluated if harvested stormwater could meet reuse standards without additional treatment • Background (at TOW- 1 ) and Pump Station Discharge (PD- 1 ) sampled monthly • Primary Constituents (monthly) - Fecal Coliform - Biochemical Oxygen Demand - Total. Suspended Solids - Turbidity - pH to - Iron • Primary and Secondary Drinking Water Standards and Giardia/Cryptosporidium (3 times) 7 ©Jacobs 2023 Results Harvested Water Quality Assessment There are no primary and secondary drinking water constituents which would preclude using harvested water as a supplemental water source ■ Inorganic Constituents Aluminum, Iron and Color - Some minor exceedances for both TOW-1 and PD- 1 , but these levels do not prevent water from use as supplemental water source - PD-1 Iron and Color exceedances related to wet well debris (issue resolved after cleaning) ■ No Volatile Organic Contaminants and Synthetic Organic Contaminants, Radionuclides, Asbestos or Dioxins/Furans were detected. to 9 ©Jacobs 2023 After startup, harvested water quality met all reuse standards TOW-1 (Background) PD-1 (Harvested Water) Month Date FC BOD TSS Turbidity pH Iron FC BOD TSS Turbidity pH Iron 0 Aug-21 U NIT N/T N/T 5.3 1.1 N/T 22 7.8 8.2 N/T N/T 1 Sep-21 U N/T N/T N/T N/T N/T N/T U 6.2 4.2 7.2 2.4 2 Oct-21 U N/T N/T N/T N/T N/T N/T U 5 11 7.0 2.1 3 Nov-21 U N/T N/T N/T N/T N/T N/T U 33 20 7.0 12 4 Dec-21 U NIT NIT NIT NIT NIT NIT U 17 22 7.0 9.4 5 Jan-22 U U U 0.1 5.08 0.62 U U 78 50 6.88 5 6 Feb-22 U U U 0.1 4.96 0.67 U U 57 73 8.18 29 7 Mar-22 U U 32 7 5.06 0.62 U 4.7 U 2 6.85 1.1 8 9 May-22 U U U 0.1 5.3 0.52 U 5.1 2.6 3 7.38 0.96 10 Jun-22 U 2.1 U 0.2 4.51 0.42 U 2.3 U 3 6.70 1.1 to 11 Jul-22 U U U 0.2 4.73 0.57 U U U 3 6.72 0.99 12 Aug-22 U U U 0.1 4.77 U U U U 4 6.83 1.2 13 Sep-22 U U U 2 5.00 0.62 U U U 7 6.86 1.2 = Public-Access Reuse Standard Parameter FC= Fecal Coliform BOD = Biochemical Oxygen Demand TSS = Total Suspended Solids 10 ©Jacobs 2023 Harvested water quality is suitable for use as a supplemental water source ■ Met all public-access reuse standards. ■ No Giardia or Cryptosporidium were detected. ■ No other potential contaminants that would affect public health or use as a supplemental water source for the reclaimed water system. ■ Filtration and high-level disinfection facilities not required, but maintenance chlorination equipment may still be warranted. to 11 ©Jacobs 2023 Results Harvested Water Quantity Assessment Estimated Pond 6 stormwater runoff was 18 million gallons per year Outlet Control • 12-month Pilot Study Rainfall = 54.89 inches x- Structure \,, 6"Discharge FM to y.,. • Existing stormwater ;�►,, 1991 -2020 Annual. Average Rainfall = 53.35 Stormwater : de., `ystem Outlet Pond 6B s p;-i, 1 Manholes c, , inches oft TOW-5 ,,,,,EB'fk 6 --- 4h, , ,j Method Annual Avg. Annual Effective Annual Runoff . _ Precip. Runoff Runoff Volume (inches) (inches) Coefficient (MG) _ T - y4 Simple 54.89 17.4 0.318 16.6 n 0 Stormwater L Pond 6A USEPA NSC 48.34 16.2 0.335 16.1 m x TOW-3 TOW-4 USEPA NSC 54.89 18_ 0.335 3 l' SW-1 CO-2 adj. i MG = million gallons; NSC = National Stormwater Calculator to Ponds 6A/6B 1 Drainage Basin OW-1 TOW-2 Total- 36.62 acres . �,,�' \ „ Pervious — 22.81 acres . . y co-1 Impervious — 12.33 acres 13 Water Surface — 1 .48 acres ©Jacobs 2023 Current state regulations do not allow stormwater harvesting systems to pump below the pond's Normal Water Level Littoral zone creation Outfall structure Sod—\ • Stormwater extraction T.O.B. (If required) 58.0 feet 1 i Peak attenuation (If required) Weir limited to pond reuse _ _ Lii _"i#4'4-67-3 volume and demonstration 4 - I _,NWL Outflow pike that permanent pool is not Average water i in table elevation 6 1 Reuse volume •1111 '- ' ' impacted. II li-f' Permanent pool • N o adverse rse h d ro to i s 1 (Max. depth = 12 ft.) "pi 56.0 feet y g 2 �1=� impacts to adjacent b. AI wetlands or other surface waters. p Il.-II=II,-Ih r1 II,T to Study Operating Level 1 .5 feet below Normal Water Level 14 ©Jacobs 2023 Daily operational data was key to understanding system response to rainfall and pumping events and harvested stormwater yields - - -Stormwater Pond 6B Operational Set Point Elevation Stormwater Pond 6A(Stilling Well Data) 60 Stormwater Pond 6B End Stud • Rain(Manual) Pond 6B Overflo 59 • HW Pump Volume +.5 °� Weir ELCD co r— Start Study o , — . . — . . — . . — • • — . • . . . . — . . — • I — • 4.0 o I E I w vl 57 ••• • I 3.5 Ecu 0 L 1 • • f.... I = v I . • a c .. \\XVI a) z 56 �{S •• , • •% I 3.0 v j l I V i 1 • % ‘I o c J I • • • • • 1 > rTz v co 55 INX %Noe I • • 11 • 1% 2.5 To c., < 54 • I i • A1•• 1I 2.0 04 Q I ro I p I• z 53 I • • • • I 1.5 c I • • • I I 52 I • • • • I 10 N I. ° f • y • •• •• • • • •• • • • • • I = ( "1"b16 ) 51 • 1 ••• • • • f • •• •• 0.5 • • a0%••1.4 • • • •• 1 » • i J • 1 50 rLMh■1 _ _ • . • , , - - —! 41 00 8/1/2021 9/20/2021 11/9/2021 12/29/2021 2/17/2022 4/8/2022 5/28/2022 7/17 22 /5/2022 15 OJacobs 2023 Average monthly pond levels show steady decline despite normal annual runoff to Pond 6 58.0 -6B Average Level -6A Average Level I 6.0 • Pond 6B average -Runoff Volume Linear (6B Average Level) - Linear (6A Average Level) monthly level never 57.0 exceeded 56 feet. ........................... . Upward trend in pond Pond SetPoint6BN W l L = runoff beginning in 56.0 ------ 4.0 "c January did not result 02 in significant increases > Pond 6B Z44 """......--- . Set Point 2 in average pond levels. c 55.0 - 3.0 E c > ■ Pond water levels W declined over study Pond 6B 54.0 - -Set Point 3 2.0 period. c - • Water level data to 53.0 - 1.0 suggest some extraction of shallow groundwater beyond 52.0 - 0.0 influence of the titi titi titi titi titi titi titi titi titi titi titi titi Se'Q 061/4 �,oJ Qf, sac 4,eo �a� QQ'k" �aA i vJv Qg� storm wat e r ponds. i 16 ©Jacobs 2023 The pilot study total annual yield was 15 times lower than the current supplemental water demand of 209 million gallons per year Percent Percent • Tested several operating Pond 6B Volume of Total Capture of levels for pilot study. Level Pumped Volume Annual Pond Percent of • 4.6 MG pumped at the NWL (feet) (MG) Pumped 6 Runoff No. of Days Study Period of 56 feet, or 33% of total >_ 54.5 12.22 87.1 66.8 249 69.4 pumped. >_55.5 6.27 44.7 34.3 163 45.4 • 12.2 MG pumped at >_ 54.5 >_ 56.0 4.63 33.0 25.3 39 10.9 feet, or 87% of total. < 54.5 1 .80 12.8 9.8 110 30.6 • Unlikely to be able to run full-scale systems at Total 14.02 100 76.6 - - operating levels below the r° NWL. MG = million gallons NWL = Normal Water Level 17 ©Jacobs 2023 Harvested water yields at all operating Levels were marginal when compared to peak supplemental water demands 40.0 - • Peak supplemental water Typical Peak Demand/Low demands normally occur 35.0 - Rainfall Period during low rainfall/runoff months. 30.0 - ■ June harvested water yield 25.0 - only 1 .6% of peak demand. • May—July Demand: 20.0 - 95.3 million gallons E 15.0 - • May—July Supply: 1 .7 million gallons 10.0 - to 5.0 - 0.0 - - i ,��� . Sep-21 Oct-21 Nov-21 Dec-21 Jan-22 Feb-22 Mar-22 Apr-22 May-22 Jun-22 Jul-22 Aug-22 Pumped Volume>=56 Pumped Volume>=54.5 Runoff Volume —0-2035 Supplemental Water Need 18 ©Jacobs 2023 Significant deficits also occur between peak daily demands and stormwater yields ■ Without significant storage, 4 1 facilities must provide on- =Current Peak Day Supplemental Demand demand capacity for peak day Pumped Monthly Average Day Flow >= 54.5' 0.9 .. 3.5 flows. 0 3 08 ■ Number of Stormwater � 0.7 0 Harvesting System facilities E this size to meet highest peak 0 2_5 0.6 < v day augmentation demands: 2 0.5 — April.: 37 systems v — May: 388 systems 0.4 v a) 1.5 Q fl, — June: 144 systems 0.3 — July: 14 systems >, 1 = 0 0.2 — August: 38 systems to 1 0.10 0.1 a 0.5 48 0.1 v .05 0.0 0.00 'e 0 0.02 0 u ,1,\ .1,1\ ,,1,'\ .1,,\ ,'11' ;11' ,�1' 1.1' ,'y'L ,1'L '11' 1'L �e9 oO. �o' vec �a� ,,eio ,va� QQ� a� �J, ,J� PJ� 19 ©Jacobs 2023 Retrofitting existing roadway stormwater management ponds is not a dependable or economic supplemental water source for CCUA's Reclaimed Water System ■ Supplemental water demands are significantly higher than harvested water supply. ■ Pumping below the Normal. Water Level did not significantly increase the amount of harvested water in peak demand months when runoff volumes are lower . ■ Operating below the Normal. Water Level requires changes to current state regulations. ■ Without storage facilities, stormwater harvesting systems must provide on- demand capacity for all flows, increasing the cost and complexity of the to supplemental water system. ■ Minimum of 110 million gallons of storage is required to meet peak monthly and daily supplemental water demands. 20 ©Jacobs 2023 Retrofitting existing stormwater management ponds is not a dependable or economic supplemental water source for CCUA's Reclaimed Water System (continued) _ _ ?� ; ■ Anyfuture consideration of stormwater { -� f- harvesting as viable supplemental water y • -� _ , source should target/include: �es • _ '..��'� � �,. - Planned regional stormwater treatment �= „ ..:, facilities - Large-scale planned/new residential and/or commercial. developments itft- Couple with large-volume storage facilities , I , - l to (that is, surface water/reclaimed water ;��4', '--+4'Kl< it: ii; storage reservoir[s]; aquifer storage and , recoverywells) 1p 21 ©Jacobs 2023