CITY OF LOMITA CYPRESS WATER PRODUCTION FACILITY OFF-LINE TESTING

Transcription

1 CITY OF LOMITA CYPRESS WATER PRODUCTION FACILITY OFF-LINE TESTING

2 2 Good Results Title 22 Requirements California Department of Public Health monitors wells throughout the state Title 22 reports Lomita s well water meets all regulatory limits, except manganese which is removed by the Cypress treatment facility Manganese of 85 micrograms/l in well water, is reduced to non-detectable in the finished water

3 3 Cypress Water Production Facility History 2010 Shut down well after two months - Taste and odor probably sulfide organics - Deposits probably calcium carbonate City Public Works Department made improvements - PCH water line replacement - MWD connection to blend waters at the tank - Aeration and mixing in the tank - Feasibility study

4 4 Council Authorized Off-Line Testing and Established Test Goals in September 2012 City Council Established Off-Line Test Goals Hardness at milligrams/liter (mg/l) Total Dissolved Solids at mg/l Palatable Taste

5 5 Groundwater Quality Natural groundwater minerals include calcium, iron, manganese, magnesium and chloride Different forms have distinctive taste Some compounds leave mineral deposits Combinations of mineral compounds are measured as alkalinity, hardness, or total dissolved solids

6 6 Lomita s Tools for Producing Good Quality Water Sodium hypochlorite injection 1. Sodium hypochlorite for disinfection and converting mineral compounds, later combined with ammonia, like MWD Ammonia injection

7 7 Lomita s Tools for Producing Good Quality Water 2. Greensand filter to remove oxidized iron and manganese Greensand filter

8 8 Lomita s Tools for Producing Good Quality Water 3. Blending with imported water Blending connection MWD water service from West Basin (Zone 2)

9 9 Lomita s Tools for Producing Good Quality Water 4. Aeration and mixing INSERT IMAGE Tideflex valve for aeration at tank inlet Mixer in Cypress Tank

10 10 Methodology Inspection, repairs, cleaning, start up, planning Three weeks of off-line testing and producing water Laboratory analysis and tasting

11 11 Cypress Water Production Facility (WPF) Greensand Filter

12 12 Water Heater & Dishpan Test Making adjustments to prevent calcium carbonate deposits Hot water in a dishpan Plates, glasses and aluminum soaking in hot water

13 13 Good Results Met all water quality objectives Total Dissolved Solids: within the mg/l range Hardness: within the mg/l range Palatable Taste: ready for community tasting Comparable: to MWD import water

14 Results - Total Dissolved Solids Graph 1000 shows the well water is about 800 mg/l and blended water hits Well 5 Raw Water the 900target Water from the Cypress Tank meets Lomita's total dissolved solids target of mg/l. 800 Insert Graph Title Total Dissolved Solids (mg/l) % of Max Nitrification Rate Blended Water from Tank 100% 90% 80% 70% 60% 50% 60% Well: 40% MWD 50% Well: 50% MWD INSERT GRAPH KDO = 0.5 KDO = % 30% 20% 10% 0% DO Concentration (mg/l) 14

15 Results - Hardness Total Hardness as CaCO3 (mg/l) % of Max Nitrification Rate Well 5 Raw Water Blended Water from Tank 100% 90% 80% 70% 60% 50% 60% Well: 40% MWD 50% Well: 50% MWD Water from the Cypress Tank meets Insert Lomita's Graph hardness Title target of mg/l. INSERT GRAPH KDO = 0.5 KDO = % 30% 20% 10% 0% DO Concentration (mg/l) 15

16 16 Recommended Long-Term Operation Chlorination: Adjust throughout the year to maintain a residual of mg/l Aeration: Continue to promote aeration to enhance mixing inside the Reservoir Blending: Continue to blend Lomita groundwater and imported MWD water for a reliable and economical water supply Make operational adjustments: to meet water quality goals and prevent corrosion & deposits

17 17 Recommended Next Step - Community Outreach & Tasting Starting 12/03/12 Blind tasting of three waters Lomita s blends and MWD alone - Ask: Are these waters acceptable - Record the names & answers - Share and use the feedback

18 18 Community Outreach / Public Education The Community Outreach / Public Education campaign will be conducted by Hazen and Sawyer and will consist of the following approach: 1. Conduct at least one community meeting to educate and survey opinions and concerns regarding the groundwater quality 2. Conduct taste testing at City Council Meetings and select Commission/Board Meetings. At these meetings, the public will be invited to participate in the taste testing as well 3. Conduct meetings and taste testing at local meetings of service clubs and other community organizations

19 19 Community Outreach / Public Education Cont. 4. Utilize the City s website, city newsletter, and possibly newsprint to disseminate information and educate the public on water issues 5. Where feasible, maximize the use of social media (i.e., Facebook) to educate the public 6. Utilize print media in the form of brochures and/or mailers to be placed with customer s water bills to educate the public 7. Utilize the local cable channel to broadcast educational information, where feasible

20 20 Recommendations to the City Council Receive a presentation from Hazen and Sawyer on the water quality data results Authorize Staff to proceed with preparation of the CWPF and related water facilities for reactivation of the CWPF with a target date of mid February 2013 for distribution of water to Lomita customers Authorize Staff to direct Hazen and Sawyer to commence with the Public Outreach / Public Education Program

21 21 21 CITY OF LOMITA CYPRESS WATER PRODUCTION FACILITY OFF-LINE TESTING DISCUSSION?