PUBLIC NOTICE on 6-14-06
Salt Lake County Service Area #3 (Service Area #3) and the Town of Alta
The water systems of the Service Area #3 and the Town of Alta were given a second 2-year extension to their Antimony Mcl exemption by the Utah Drinking Water Board at their February 27, 2004 meeting. The reasons for this exemption are outlined below. We the Service Area #3 and the Town of Alta have continued to test our water over the last 9.5 years. The levels of antimony in the Service Area #3ís and the Town of Altaís water sources is 6.7 ug/L and 9.6 ug/L (6.7 parts per billion and 9.6 parts per billion) respectively. These levels exceed the EPA drinking water standard of 6 ug/L (6 parts per billion).
Antimony is an inorganic chemical that occurs naturally in soils, ground water and surface waters and is often used in the flame retardant industry. It is also used in ceramics, glass, batteries, fireworks and explosives. It may get into drinking water through natural weathering of rock, industrial production, municipal waste disposal or manufacturing processes. The Service Area #3 and the Town of Alta have found no evidence that industrial production, municipal waste disposal or any manufacturing processes have contributed to the presence of antimony in our water sources.
Prior EPA research on laboratory animals such as rats that were exposed to high levels of this chemical during their lifetime did show that this chemical decreases longevity and can alter blood levels of cholesterol and glucose.
The Service Area #3 and the Town of Alta contracted with Aqua Environmental Services, Inc. in the summer of 1996 to do extensive research on the subject of the long-term effects of antimony on humans, possible full-scale treatment, related costs associated with the removal of this chemical and possible alternative water sources. That study found the following:
"As a practical matter, there are insufficient data to indicate either the acute or chronic toxicity hazard that may result from the assimilation of antimony".
There is no real data available that proves that antimony is any more toxic than copper, which has a drinking water trigger level of 1,300 ug/L (1,300 parts per billion), or roughly 217 times the level allowed for antimony. EPA has set drinking water standard for antimony at 6 parts per billion or 6 ug/L.
There is no proven technology available that will remove antimony to the levels that have been promulgated by the EPA (6 parts per billion).
The Utah Division of Drinking Water has reviewed this situation, including the aforementioned study, and has made the following findings and conclusions with the concurrence of the Utah Drinking Water Board:
Health effects data for antimony, first regulated in 1993, in drinking water are inconclusive, and appear to represent a minimal hazard to the resident population for the next five years.
The initial antimony exemption was for a five year period, beginning January 1, 1997. In January of 2002, the Service Area and the Town of Alta presented the Drinking Water Board with our research and asked for an exemption extension. The first 2 year extension was granted on 3-1-02 by the DWB. The Service Area and Town of Alta again went before the Drinking Water Board in January of 2004 and were granted a second 2-year exemption extension.
The 2-year exemption extension will be allowed provided samples are collected at six (6) month intervals throughout the two-year period for sources where antimony exceeds the MCL. This public notice will be re-issued every six months over this time period to inform the resident population. The Service Area #3 and the Town of Alta agree to implement immediate solution to the problem should testing show that levels of antimony exceed 50 ug/L in the distribution system.
The EPA or any other group has not developed full-scale treatment information and cost data for antimony at this time. The Division of Drinking Water will encourage the water utilities and their engineer to work with the EPA to gather this data. The Service Area #3 and the Town of Alta have spent in excess of $160,000 on testing 23 methods of treatment. We have had success with 7 technologies for removing Antimony to below EPA standards. A cost analysis of these technologies shows that our water rates could increase significantly, although the processes we are currently testing seem to be a viable solution at a reasonable cost. We will continue to research solutions and have requested that the EPA revisit the standard adopted in 1993 with the current thinking for health thresholds represented in the 1996 Safe Drinking Water Act Amendments.
In May of 2005 the Service Area received approval from the Division of Drinking Water to begin a Blending and Averaging plan to see if it is a viable solution for meeting the Antimony MCL. This plan involves optimizing the use of our Peruvian source water blended with the Wasatch Drain Tunnel water to meet the MCL. If you should have any questions or require any additional information about this plan please contact Keith Hanson with Salt Lake County Service Area at (801) 278-9660 or his email address is email@example.com