The Chicago Tribune has published three articles in the last two weeks regarding the quality of the City of Chicago’s drinking water. The first article reported on lead levels in the drinking water treated by the City of Chicago, a second article addressed “Toxic chromium found in Chicago drinking water,” and the third article discussed the levels of pharmaceutical and personal-care-product residues present in the water.
Evanston’s drinking water is treated by Evanston’s water treatment plant at Sheridan Road and Lincoln Avenue. Because the water comes from the same source – Lake Michigan – as the City of Chicago’s, Evanston officials issued two prepared statements summarizing the City’s test results of these compounds and how they meet the current regulations.
Lead Levels Well Below the Maximum Allowed
The City of Evanston’s Utilities Deparment completed tests for lead in water as required by the Lead and Copper Rule during the week of Aug. 1. The City says it has used a blended poly/orthophosphate in treating water since July 1992 and that “this treatment process is very effective in reducing lead levels in the water.” The City found that the lead levels were well below the level required by the rule, and it summarized the test results as follows:
”The results were that the City maintained compliance to the rule (which it has done continuously since November of 1992) in that the 90th percentile value for lead was below the 15 parts per billion (ppb) action level required by the rule. In fact, the 90th percentile in Evanston this year was again less than 5 ppb, which is the detection level used by Underwriters Laboratories (UL) who were contracted to perform the analyses. Additionally, measurable lead was only detected in two of the 30 homes tested and these levels were 5.1 and 6 ppb, still almost three times less than the action level of 15 ppb.”
The City’s Utilities Department said it concurs with a statement in the Tribune articles that if homeowners turn the tap water on for a few minutes before drinking it to remove the water that has been in contact with lead pipes or fixtures (brass also contains a small amount of lead), it will greatly reduce exposure to any lead. Evanston officials say, however, “Water that has been left standing in the pipe for 6-8 hours will possess lead levels that are still very low and in most cases at a level below the detection level.”
Levels of Chromium (CrVI)
Chromium is a metallic compound found naturally in rocks, soils, plants, and volcanic dust as well as in humans and animals. Total chromium is made up of trivalent chromium (an essential nutrient for humans), hexavalent chromium and the metallic form of chromium. The primary source of CrVI in drinking water supplies is discharges from steel and paper manufacturing facilities.
The City says the USEPA is asking that all large water suppliers collect data to assist the agency in determining if hexavalent chromium should be regulated in addition to total chromium, which is currently regulated with a Maximum Contaminant Level (MCL) of 100 parts per billion (ppb). As reported by the Tribune, the State of California has instituted a public health goal of 0.02 ppb for CrVI. While this level is not mandated as an MCL designation at this time, the City says that research done by the State of California has prompted the USEPA to take a closer look at regulating CrVI.
In its most recent testing for CrVI in July, Evanston found that there were 0.40 ppb of total chromium and 0.23 of hexavalent chromium in the water. While this is well below the maximum level designated by the current federal regulations, it exceeds the goal instituted by California.
City officials say, “The levels of both total and hexavalent chromium found at Evanston are very similar to what has been found in all Lake Michigan water treatment locations in Illinois, Indiana and Wisconsin. The City of Evanston will continue to collect and analyze data on chromium in order to be prepared for any changes in regulations.”
The City adds that additional studies are underway to determine if the State of California goal is based on solid enough scientific data to warrant an MCL designation at this level. “There is a lot of debate in terms of the transformation of CrVI to trivalent chromium in the human body as the compound passes through the
digestive system and it is clear that additional studies are necessary,” City officials say.
Pharmaceuticals and Personal Care Products (PPCP)
Pharmaceuticals and personal care products found in drinking water stem from the use of prescription and over-the-counter drugs as well as from products such as insect repellents, tobacco and agricultural use by products, say City officials. In most cases the occurrence of these compounds in water is due to the normal passage of the compound through the human body as well as improper disposal of the materials.
City officials say the City began testing Evanston drinking water for these compounds in May 2008. It says it detected gemfibrozil (cholesterol medication), perfluorooctane sulfanate (a product used to manufacture Scotchgard), and cotinine (a by-product of nicotine) at very low levels – in the range of 0.001ppb to 0.0021ppb. The City says, “There is no science to determine what, if any, deleterious health effects may exist from these extremely low levels,” and adds there is currently no MCL designation for these compounds.
The testing for these compounds will continue on an annual basis so that if regulations are established, the Water Division will already have a baseline of data to use in the selection of a proper treatment technique, the City says. The City adds, “Evanston Water Division is committed to stay at the forefront of testing and
treatment technology and will continue to provide safe drinking water to the residents of Evanston and our wholesale water customers.”