Oconee County Utility Department. Water Resources Mid-Year Update January 18, 2017

Transcription

1 Water Resources Mid-Year Update January 18, 2017

2 Water & Wastewater Planning Carter & Sloope, Inc. Marty Boyd, P.E. Engineered Horizons, LLC Paula Feldman, P.E.

3 Planning Presentation Outline Water demand forecasts & capacity needs Water supply and treatment options Wastewater forecasts & capacity needs Wastewater treatment options Proposed planning data: ERCs

4 Background 2005 Wastewater Strategies Plan Much has changed since the 2005 Plan Drought of record ( ) Great Recession Slower growth but growth is returning Perfect time to look forward at water and wastewater infrastructure needs

5 Steps in the Planning Process Develop water demand and wastewater flow forecasts through 2050 Identify key planning metrics Develop and evaluate strategies Water supply & treatment Wastewater treatment Water distribution and wastewater collection Recommendations

6 Forecasting: Identify Future Needs Data collection and review Develop Oconee County water usage statistics Develop water/wastewater usage forecasts Combine community vision, population forecasts, service goals and usage statistics Forecasts through 2050

7 Historic and Future Population Population Year Historic Population OPB Projections 2005 Strategic WW Plan Oconee County 2007 Comp Plan MACORTs 2014 Study (based on '07 Comp Plan)

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9 Water System Map

10 Sewer Service Areas

11 Population Forecasts

12 Water System Statistics 9,400 Water Customers in 2015 ~75% of water demand is residential Population served ~ 70% 2015 Water Usage: 2.53 MGD, Avg Annual Day Total per capita rate: 101 GPD / person in 2015 Residential per capita rate: 68 GPD / person Non-revenue water ~ 17%

13 Water Supply & Treatment UOBWA: Bear Creek reservoir & WTP UOBWA Member Permitted Reservoir Withdrawals Entitlement Monthly Share Average Max Day (MGD) (MGD) A-CC 44% Barrow 19% Jackson 25% Oconee 12% Total 100% CURRENT Water Treatment Plant Capacity UOBWA Member Entitlement Share Max Day (MGD) A-CC - - Barrow 38.1% 8 Jackson 42.9% 9 Oconee 19.0% 4 Total 100% 21 Groundwater wells 4 wells in operation in 2015: 0.15 MGD

14 Water Demand Forecasts Water Demand (MGD) Year Avg Day Demand Max Day UOBWA Share Water Supply Max Day UOBWA Share WTP Capacity Max Day

15 Water Supply & Treatment Needs Adequate raw water supply from UOBWA through Reaching existing WTP Capacity at UOBWA Need access to 1 to 2 MGD of treated water by 2020

16 Water Treatment Options Short-term need for additional water treatment: Discussions underway with UOBWA to lease/purchase excess entitlement shares from other members Expansion of UOBWA WTP Hard Labor Creek: 15 MGD water supply

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18 Wastewater

19 Wastewater System Statistics ~2,100 wastewater customers in 2015 ~13% of population has sewer service ~ 30% of wastewater flow is generated by residential customers Total WW Flow in 2015: 0.98 MGD Per capita rate: 146 GPD / person in 2015 Inflow/Infiltration (I/I) average for 2014 and 2015 = 34%

20 Existing Wastewater System

21 Wastewater Flow Forecasts Wastewater Flow (MGD) Year Avg Day Flow Max Month Avg Day Flow Total Existing Treatment Capacity (Rocky Br LAS and Calls Cr WRF)

22 WW Treatment Capacity Needs

23 Treatment Plant Existing System Shortterm Option 1 Option 2 Option 3 Calls Creek Abandon Jimmy Daniel PS Rocky Branch Middle Oconee Total Capacity Abandon Epps Br Rd PS 1.0 Discharge 0 Abandon Discharge 1 MGD to Barber Creek Middle Oconee WRF Abandon Rocky Br LAS, discharge to sewer Discharge 1.5 MGD to Calls Creek Wastewater System Options

24 Capacity Planning: ERCs Equivalent Residential Connection (ERC) Purpose for ERC: Assess capacity impacts for proposed development Current ERC (or ERU) 208 gpd / residential connection

25 Capacity Planning: ERCs Calculate updated ERCs based on current Oconee County residential water usage Proposed ERC is Water: 220 gpd / residential connection Wastewater: 260 gpd / residential connection

26 Commercial Capacity Requests Replace Table JT-1 for estimating commercial water demand and wastewater flows Updated benchmarking of usage based on land use type and efficient fixtures Recommend using gpd/square ft

27 Implementation

28 Water Supply Drought Resiliency Optimize Water System Flow, Pressure and Delivery New Elevated Storage Tank in Watkinsville area Establish Northern / Southern Pressure Zone Establish NW Pressure Zone

29 NW Oconee Pressure Zone

30 Wastewater Capacity Calls Creek WRF Upgrade Why the Calls Creek site? Schedule Cost effective Ease of expansion

31 Calls Cr WRF Upgrade - Delivery Design / Build Team General Contractor Crowder Construction Engineer Constantine Engineering Project design expands plant from 0.67 MGD to 1.5 MGD. 80% design is complete. Contractor has submitted an 80% GMP. Anticipated construction start date is April 2017, pending Board authorization.

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33 Permitting 1.0 MGD Oconee County currently has a NPDES Permit and approved Design Development Report (DDR). An amended DDR has been submitted; received EPD concurrence. Revised plans and specifications to be submitted.

34 Permitting (Continued) 1.5 MGD A Waste Load Allocation has been approved. A NPDES Permit to discharge 1.5 MGD will be submitted. An EID will be prepared and include a public meeting with 30-day notice. Submittal of DDR. NPDES permit application for 1.5 MGD will be prepared and placed on 30-day public notice. Permit is typically issued within 60-days after public notice.

35 Existing 0.67 MGD Treatment Process

36 Clogging Problems with Membranes Decreases Hydraulic Capacity

37 Original Proposed 1.0 MGD Treatment Process Included New Membranes

38 Proposed 1.5 MGD Treatment Process

39 Selected Treatment Process 3-stage biological process includes biological phosphorus removal (BNR) technology Reduces chemical costs for phosphorus removal Effluent filters are proven in hundreds of applications.

40 New Effluent Outfall Existing 10-inch effluent outfall will be replaced with new 16- inch outfall.

41 Calls Creek WRF Upgrade Budget Discussion

42 Original Upgrade Proposal Item Description Cost ($ M) Cumulative Cost ($ M) Added Plant Capacity Cum. Plant Capacity Cum. Cost per Gallon ($/MGD) I. Existing plant before construction a. Includes 3 membrane cassettes: (0.667 mgd) II. Cost to implement new capacity $ $ 8.78 a. Package plant purchase, deliver, erect $ b. Sitework to place package plant online $ c. Other work req'd by design drawings $ III. Existing Plant Rehabilitation $ $ 7.50 a. Replace 1 membrane cassette $ IV. Existing Plant Rehabilitation $ $ 5.89 a. Replace 2 membrane cassettes $ V. Redundancy for firm capacity $ $ 6.57 a. Add 2nd clarifier at package plant site $ VI. Future plant expansion to 3 MGD $ $ 6.16 a. Add next package plant $ b. 10% $ c. 15% $ 0.954

43 Revised Proposal & Design - GMP 80% GMP Budget $13.5M 47% 5% 7% 5% 36% Permit & Final Design Construction Equipment Const Mgmt Contingency

44 Sewer Collection & Transmission

45 McNutt Creek Gravity Sewer Phase II PS Construction: November 2016 May 2017

46 Epps Bridge Road Force Main Upgrade Mars Hill Rd Loop 10 Construction: January to July 2017

47 Future Alternatives

48 WRF Site Alternatives: Middle Oconee Calls Creek

49 Basin: 40,000 Acres 35% Total Land Area Oconee County Utility Department Middle Oconee Gravity Flow:

50 Middle Oconee Gravity Flow: Bogart Mars Hill Rd Basin: 40,000 Acres 35% Total Land Area Watkinsville

51 Basin: 3,600 Acres 3% Total Land Area Oconee County Utility Department Calls Creek Gravity Flow:

52 Watkinsville Oconee County Utility Department Calls Creek Regional PS: Bogart 78 Hwy 78 RBR JDR 316 Epps 10 DBR Mars Hill Rd MO

53 Existing 18 Gravity Sewer

54 Existing 18 Gravity Sewer

55 Existing 18 Gravity Sewer

56 Existing 18 Gravity Sewer

57 20 Sewer Easement 25 Stream Buffer Creek Typical Sewer Easement 24 Gravity Sewer

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