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Beach Chalet Soccer Fields - Water Usage Analysis of Grass vs. Artificial Turf
- 1. .......................................................... Page 1 of 5 Water Usage Analysis This analysis is an update of a paper prepared for the California Coastal Commission hearing. Time and materials are donated to the Yes on H and No on I campaign. Murphy Windmill One of two windmills built to pump irrigation water from the aquifer under Golden Gate Park. BEACH CHALET SOCCER FIELDS LIVING GRASS VS. ARTIFICIAL TURF WATER USAGE ANALYSIS Prepared by SF Ocean Edge October 19, 2014 www.sfoceanedge.org ........................................................................................................................................................................ The San Francisco Recreation and Park Department has repeatedly stated that installing artificial turf at the Beach Chalet Athletic Fields is environmentally beneficial. One of the claims for environmental benefit has been that water will be saved by using artificial turf instead of living grass. However, a closer look at the facts shows just the opposite - water will be lost to the aquifer and the public will be paying the cost of sewage treatment for millions of gallons of water because of this project. The current irrigation water for the Beach Chalet area comes from the aquifer under Golden Gate Park, and a great deal of it is returned to the aquifer through soil percolation. With a few exceptions of plantings that need special water supplies, Hetch Hetchy water is not used to water most of Golden Gate Park. RPD water usage figures used in the official documents are incorrect. RPD commissioned a study of water usage based on WUCOLS. (WUCOLS is a formula established by the State to help show how much water might be used in irrigating a landscape.) The result from using this formula was 5.7 million gallons irrigation water needed for all 4 of the Beach Chalet fields. It is not known if the foggy conditions that prevail at Ocean Beach were taken into account in this abstract calculation. But internal e-mails, discovered during a routine Sunshine request, show that Ana Alvarez, the RPD Superintendent of Parks & Open Spaces, had written to Dan Mauer, the RPD Capital Project Manager for the Capital Improvement Division, to disagree with the 5.7 million gallon figure: "I was surprised to learn the number on water use that has been used by Capital to describe the field maintenance practices as part of the project proposal. It appears that the number was based on assumptions and without the participation of my staff. Since the delta on water consumption is significant (4x of actual use), I would like to better understand your calculations." (2-7-2013 Alvarez Email #1) Alvarez forwarded an email to Mauer from Steve Castile, the RPD Golf and Turf Manager who went out to the fields and measured the actual amount of water that is used at Beach Chalet. The figure Castile came up with is "the total usage is between 1.3 and 1.5 million gallons." Mauer's response to Alvarez and Castile is: "Not sure we need to beat this one up too much but would be interesting to compare the two side by side. The good thing is that we are saving water."
- 2. RPD has never corrected their estimate to reflect the lower, actual water usage. The City did not mention this actual usage to the California Coastal Commission or the public; rather, they have continued to use the 5.7 million gallon figure in their presentation booklet to the Commissioners and in the summary sheet that they submitted to Coastal Commission staffer Kevin Kahn "SF R&P, Beach Chalet Athletic Fields Maintenance: Current/Grass vs. Planned/synthetic Turf." The figure is also being quoted in campaign literature for Yes on I. The Beach Chalet project will result in a loss of 3.1 million gallons of rainwater to replenish the aquifer under Golden Gate Park. In the attached emails, Mauer states that the project would save water, even if the water usage were 1.5 million gallons. The following calculations show that this assumption is incorrect. Not only is the project NOT saving water, the project would cost water that should be going to the aquifer. Using the following calculations, we estimate that 4.4 million gallons of rainwater falls on the 7.2 acres every year: Average rainfall for SF = 22.28 inches per year (source: FINDTHEDATA.ORG) Square inches in 7.2 acres = 45,163,008. Cubic inches of rain in 7.2 acres (45,163,008 x 22.28 = 1,006,231,818.24 cu in.) # of gallons in a cubic inch (0.004329) Therefore, gallons of rain per year - (1,006,231, 818.27 x 0.004329 = 4,355,977.54) Due to concerns about potentially toxic chemicals in the artificial turf possibly entering the aquifer, the SFPUC has required that the project route all rainwater that falls on the fields to the sewage treatment plant. San Franciscans will be drinking the water from the aquifer in a few years. Because of this required treatment, rainwater that now recharges the aquifer would instead be processed as sewage and then pumped out into the Pacific Ocean. Therefore, in the above emails, Mauer's statement of saving 1.3 million gallons at Beach Chalet is not accurate. He should have subtracted 4.4 million gallons of lost rainwater. The Beach Chalet project deprives the aquifer of 3.1 million gallons of rainwater! Water used to clean the fields was not included in the RPD calculations. Artificial turf should be thoroughly washed often to prevent bacteria build up. Dog excrement and other wildlife leavings have to be cleaned off. Is the City not planning to use a lot of water to keep the artificial turf clean? That water is not in their calculation. The public will pay the additional cost of processing rainwater as sewage. 4.4 million gallons of rainwater that falls on the fields will have to be processed at the sewage treatment plant, using energy for processing. SF rate-payers will be picking up the fees for this additional processing of clean rainwater! .......................................................... Page 2 of 5 Water Usage Analysis This analysis is an update of a paper prepared for the California Coastal Commission hearing. Time and materials are donated to the Yes on H and No on I campaign. Using a residential sewer bill, costs borne by the rate-payer would be: Sewer bills - first tier rates: 4,355,977.54 gallons of rainwater x $.012112 / gallon = $52,760.90 OR Sewer bills - second tier rates (24% higher rate for higher usage): 4,355,977.54 gallons of rainwater x .015013 / gallon = $65,397.91 - - - - - Attachment: Sunshined E-mails from within RPD regarding water usage at Beach Chalet
- 3. .......................................................... Page 3 of 5 Water Usage Analysis This analysis is an update of a paper prepared for the California Coastal Commission hearing. Time and materials are donated to the Yes on H and No on I campaign.
- 4. .......................................................... Page 4 of 5 Water Usage Analysis This analysis is an update of a paper prepared for the California Coastal Commission hearing. Time and materials are donated to the Yes on H and No on I campaign.
- 5. .......................................................... Page 5 of 5 Water Usage Analysis This analysis is an update of a paper prepared for the California Coastal Commission hearing. Time and materials are donated to the Yes on H and No on I campaign.