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Home My WebLink About09/05/1989, 5 - INFORMATION ON PRIVATE GROUNDWATER WELLS AND RECENT WELL PERMIT ACTIVITY IN THE CITY. �1��pl�Rlll�lllll�lll III �/ f � MEETING LATE: CI"y San LUIS OBISPO Se tember 5, 1989 WaGe COUNCIL AGENDA REPORT "r"" FROM: William T. Hetland, Prepared by Allen Short Utilities Director Water Division Manager SUBJECT Information on private groundwater wells and recent well permit activity in the City. CAO RECOMMENDATION Receive, review provide staff with desired direction. BACKGROUND: On April 5, 1989, the City Council approved an emergency ordinance and resolution implementing the mandatory water conservation program. The overall goal of the program was to reduce water consumption by 20 percent. As a result of the current water shortage, the City and private citizens have become interested in the development and use of groundwater supplies. The Council has expressed concern about private well development and requested information on the number of private wells in the city, current drilling activity, and possible effects on groundwater quality and quantity. We have surveyed the City and County and discussed the matter with Tim Cleath, a local hydrologist who was previously retained to assist in the groundwater development program. Based upon the best information available the number of wells within the city and the surrounding area are: Fifteen privately operated wells are within the city or in immediately adjacent county areas. There may be additional wells which have been hand dug or are not recorded on well logs. There may be about a dozen more dating from before 1950, which may or may not be used regularly. There are roughly 50 wells existing within the greater airport area outside the city limits. There are probably a couple hundred wells in the Reservoir Canyon, Stenner Creek, O'Connor Way, Country Club/Rolling Hills, and Edna Valley areas that are within the upper San Luis Obispo Creek watershed and ground water basin. The City has drilled 12 wells in its groundwater development program and is developing 5 of them. In addition, the County Health Department has issued four (4) permits for wells within the City limits for the 1988 calendar year and six (6) permits for the 1989 calendar year. The City has issued no permits for the calendar year 1988 and 1 for calendar year 1989. S'/ II�h��H��oiIIIIIIIIp 1111U city of sai t Luis OBISPO COUNCIL AGENDA REPORT Page 2 Both the Community Development and Utilities staffs have received a number of inquiries by citizens of San Luis Obispo regarding private well development. The majority of questions are concerned with process, procedure, cost and limitations. Since the implementation of the mandatory water conservation program and based upon the best available information, there has not been a dramatic increase in the number of permits or wells drilled within the City limits. The Council also has questioned and requested information on the possible effects on groundwater quality and quantity. Currently, no one monitors or regulates groundwater pumping. Private citizens, business and governmental agencies can drill wells and pump as much water as they want. Additionally, the quality of the underground basin is of primary concern. However, water quality monitoring is use dependent (private vs. domestic) and is not always required or completed. The City is required to continuously monitor each of the wells which will be used for domestic consumption. The City through this requirement has found contamination and constituents above the State established Maximum Contaminant Levels. Not all wells used by private citizens require water quality testing. However, it is recommended by both the County Health and State Department of Health Services that the well be periodically tested. Protecting groundwater quality requires keeping substances other than relatively clean water from getting into lakes, streams, and the ground. Wells recently permitted by the -� County must meet construction and sealing standards based on State requirements to protect groundwater from contamination and preserve water quality. However, older wells were not subject to these requirements and the possibility does exist that aquifer contamination could occur. We do know that the aquifer under San Luis Obispo is not continuous and uniform. It consists of several subbasins, probably created by different layers and locations of sediments and fractured rock. Some places have no usable groundwater; others do. Estimates of the amount of water that can continuously be pumped from the immediate area of the City vary, but estimates center around 2,000-3000 acre feet. However, to fully evaluate and address the City Council concerns regarding groundwater quality and quantity would require an extensive groundwater basin study by either the City, State, or an outside consulting firm. Presently, the California Department of Water Resources and City staff are developing information which will assist defining reliable yields. This information is due to be available by 1991. At this point neither water quality nor possible areas of contamination are being fully investigated. Finally, staff has been working on a report which would address well standards and adequacy of well supplies for new development projects. We will continue with that effort if the council does not favor a ban on new private wells. I <<��►Ilmll►Iliillil'�'u'�IIUpi city of sari Luis OBlspo i is COUNCIL AGENDA REPORT Page 3 A list of alternative options under investigation and City roles in regulating private wells are: A. Do nothing. Unless the county or a special district become more involved in groundwater management and overdrafting, adjudication would probably occur. City administration/enforcement costs would be minimized in the short term, but legal and utility costs could become significant in the long term. B. Require information of well drillers and operators that will help define reliable yields and eventually lead to control of withdrawals. City administration/enforcement costs would not be high initially, but would increase as the City adopted more controls. C. Regulate well drilling and/or pumping based on current knowledge. The city would allow some additional well development, but in locations presumed not to interfere with public groundwater supplies. City administration/ enforcement costs could be substantial. The attached list includes standards which could be applied to well construction, most based on existing county standards. Staff is not yet prepared to recommend pumping limits for permitted wells. D. The possibility may exist that the City can prohibit additional private well drilling. Doing so would limit new taps into the aquifers, but not the amount of pumping from existing wells. The lack of information on reliable yields, plus previous conclusions on overdrafting, indicate that this could be justified as an interim measure, perhaps as a permanent ban. City administration/enforcement costs would be minimized, though there would be some costs to this approach. RECOMMENDATION Accept the report as informational at this time. If the City Council desires to consider further action, they could discuss the following alternatives. 1. Continue to monitor the present well drilling situation (primarily those new wells done under permit). 2. Report back to the Council on the approach and cost of a comprehensive underground water yield study. 3. Have staff investigate whether the City can legally ban private well development in the city. If, by the end of March and legally approved, reservoir levels are not to 67% of capacity, consider preparing an emergency ordinance. I -15 l