Salinity Management Strategies During Drought

Transcription

1 EASTERN MUNICIPAL WATER DISTRICT Salinity Management Strategies During Drought Jayne Joy, P.E. Director of Environmental and Regulatory Compliance October 1,

2 Agenda Overview of EMWD Regional Source Water Impacts from Drought EMWD Salinity Impacts from Drought Summary of Drought Related Salinity Issues 2

3 Overview of EMWD 3

4 Overview of EMWD Santa Ana Region San Diego Region Eastern Municipal Water District: 555 square miles in West Riverside County Seven cities with more than 785,000 people District Services: Water System serve about 89,000 acre-feet/year (142,000 accounts) Sewer System treat 45 MGD (237,000 accounts) Recycled Water System serve about 39,000 acrefeet/year (316 accounts) Regional Water Reclamation Facilities: Four Regional Plants, Tertiary Treatment Watersheds: Santa Jacinto River Watershed Santa Margarita River Watershed 4

5 Regional Source Water Impacts from Drought 5

6 Southern California - Sources of Water Sierra Nevada Mountains Bay Delta Colorado River Aqueduct State Water Project Local Supplies: Groundwater Brackish Desalination Recycled Water Best Practices in Water Use Efficiency (Conservation) 6

7 Southern California System Operations SPW SPW 7

8 Operational Actions due to Drought SPW SPW 8

9 East Branch State Project Water (TDS) Total Dissolved Solids (TDS) (mg/l) Silverwood Lake Mills Effluent Average: 270 mg/l Range: 150 to 393 mg/l 9

10 Colorado River Aqueduct (TDS) Total Dissolved Solids (TDS ) (mg/l) Lake Mathews Average: 623mg/L (130% ) Range: 562 to 697mg/L

11 Drought Impacts on Water Quality Low Delta outflows High salinity near pumps 11

12 EMWD Salinity Impacts from Drought 12

13 Source Water Changes in Drought Mills Filtration Plant Perris Filtration Plant Hemet Filtration Plant MWD and EMWD Facilities Menifee and Perris Desalters & Wells Skinner Filtration Plant Pre- Drought Post- Drought Percentage (%) 40% 20% Source Water SWP SWP Percentage (%) 15% 15% Source Water SWP/CRW CRW Percentage (%) 6% 6% Source Water SWP CRW Percentage (%) 24% 24% Source Water Wells Wells Percentage (%) 15% 35% Source Water SWP/CRW 50% Blend Legend: SWP = State Water Project Water CRW = Colorado River Water CRW Point: Pre-Drought: 66% SWP and 12%CRW Post-Drought: 19% SWP and 57% CRW 13

14 Recycled Water System & Permits San Jacinto Watershed Santa Margarita Watershed = Santa Ana Region San Diego Region Regional Water Reclamation Facilities (RWRFs) (45 MGD) Recycled Water System: Fully interconnected system with a discharge structure and permitted by two Regional Boards Santa Ana Regional Board Permits: Master Permit for all reuse sites in the San Jacinto Watershed. 95% of the recycled water is used in this watershed. NPDES Permit for seasonal discharge into Wasson Canyon, no discharge since February San Diego Regional Board Permit: Reuse permit is for the Temecula Valley plant and reuse sites in the Santa Margarita Watershed. Only 5% of the recycled water is used in this watershed. 14

15 Comparison of Recycled Water and Source Water Qualities Total Dissolved Solids (mg/l) Total Dissolved Solids (mg/l) SJVRWRF Recycled Water and Source Water Qualities 200 Apr-13 Oct-13 Apr-14 Oct-14 Apr-15 TVRWRF Recycled Water and Source Water Qualities 300 Apr-13 Oct-13 Apr-14 Oct-14 Apr-15 Recycled Water Source Water Recycled Water Source Water Total Dissolved Solids (mg/l) Total Dissolved Solids (mg/l) Apr-13 Oct-13 Apr-14 Oct-14 Apr MVRWRF Recycled Water and Source Water Qualities PVRWRF Recycled Water and Source Water Qualities 300 Apr-13 Oct-13 Apr-14 Oct-14 Apr-15 Recycled Water Source Water Recycled Water Source Water KEY DATES: March 2014: Reduced use of SWP and increased use of CRW July 2014: Converted Hemet Filtration Plant from SWP to CRW July 2014 to September 2014: Blended CRW with Diamond Valley Lake Early 2015: Water Quality without Diamond Valley Lake 15

16 Salinity Management N EMWD Service Area Groundwater Basins and its General Flow Pattern Groundwater Basins Ambient Water Quality (mg/l) Canyon 340 San Jacinto Upper Pressure 350 San Jacinto Lower Pressure 800 Lakeview/Hemet North 860 Perris North 760 Hemet South 940 Menifee 2030 Perris South

17 Salinity & Nutrient Management (SNMP) San Jacinto River Watershed Groundwater Basins Salt & Nutrient Management Plan Plan protects basins water quality. Recycled water exceeds basin objectives in Lakeview/Hemet North (TDS & TIN), Perris South (TIN), and San Jacinto Upper Pressure (TDS & TIN), and these basins require mitigation activities Mitigation is accomplished with the desalination program and recharge of State Project Water TDS = Total Dissolved Solids TIN = Total Inorganic Chemistry BASIN PLAN OBJECTIVES PERRIS NORTH SAN JACINTO LOWER PRESSURE SAN JACINTO UPPER PRESSURE* PERRIS SOUTH LAKEVIEW/ HEMET NORTH HEMET SOUTH MENIFEE TDS (mg/l) (500) TIN (mg/l) (7.0) *Maximum Benefit Limits in parenthesis where objectives set to promote reuse. 17

18 Salinity & Nutrient Management (SNMP) San Jacinto River Watershed Groundwater Basins TDS = Total Dissolved Solids TIN = Total Inorganic Chemistry Salinity Changes Due to Drought There is a 3 to 14% increase in the recycled water concentrations by basin due to drought Additional mitigation is required, mitigation with State Project Water is delayed Recycled water is approaching objectives in Perris North and Hemet South Regulatory agencies allowing long-term averaging and evaluating long-term solutions Recycled Water Qualities PERRIS NORTH SAN JACINTO LOWER PRESSURE SAN JACINTO UPPER PRESSURE* PERRIS SOUTH LAKEVIEW/ HEMET NORTH HEMET SOUTH MENIFEE TDS Obj (mg/l) (500)* Pre Drought Post Drought % Increase 11% 14% 6% 10% 14% 3% 3% *Maximum Benefit Limits in parenthesis where objectives set to promote reuse. 18

19 EMWD Desalination Facilities Desalination Facilities and Program: Reverse Osmosis Process Brine Disposal in Santa Ana River Brine Line Two Desalination Facilities with a treatment capacity of 8 Million Gallons per Day 5% of EMWD s Water Portfolio In 2014, about 18,100 tons of salt was removed Groundwater Management Zones (GMZs): Perris South Basin: In 2014, about 15,900 tons of salt was removed Lakeview/Hemet North Basin: In 2014, about 2,200 tons of salt was removed Desalination Facilities and Groundwater Management Zones 19

20 Summary of Drought Related Salinity Issues 20

21 Summary of Drought Related Salinity Issues Drought conditions result in increased salinity of sources of supply causing higher salinity discharges and potential permit violations Discharge permit limits based on higher quality source water assumptions Discharge permit limitations can inhibit the use of Colorado River supplies and some local sources of water; critical supplies in reducing SWP demand Sustainability of Recycled Water Programs at risk; drought resistant water source Time to develop a solution to Long Term Drought Conditions 21

22 EASTERN MUNICIPAL WATER DISTRICT Contact Information Jayne Joy, P.E. Director of Environmental and Regulatory Compliance (951) ext