Lead in school drinking water.
The regulations governing the amount of lead in drinking water have changed over the years as the health effects of lead have become more clearly defined. The SDWA of 1974 set a maximum contaminant level (MCL) of 50 parts per billion (ppb) for lead in drinking water at the point of entry (POE), which is the point at which the water enters the distribution system whether it comes from a water treatment plant or directly from a well. Most water sources and water producers have had no trouble in meeting the 50 ppb requirement. The LCCA of 1988 called for a more stringent requirement in that it recommended an action level of 20 ppb at the point of use. More recently in May of 1991 the Environmental Protection Agency (EPA) promulgated the Lead and Copper Rule (4) which set an action level for lead at 15 ppb. Additionally the Lead and Copper Rule called for corrosion control at the water plant in cases where the lead and/or copper exceeded the action levels at the point of use. Corrosion control is intended to prevent leaching of metals from the plumbing in the distribution system, thereby reducing the amount of lead at the point of use. It is not known at this time whether or not the LCCA will be amended to reflect this newer action level of 15 ppb for lead.
Concurrent with the various actions taken on the amount of lead allowed in drinking water, new guidelines were issued by the Centers for Disease Control regarding the amount of lead in blood considered to pose a health risk. The single action level of 25 micrograms per deciliter was replaced in 1991 with five "Classes of Child," which are based on blood lead levels ranging from |is less than~10 micrograms per deciliter to 70 and above (5). Levels of 10 and above trigger various types of follow-up activities ranging from community-wide prevention to medical treatment.
Under the LCCA, schools and day care centers were encouraged to test their drinking water outlets for lead and to remediate those outlets that tested above the action level. The Act as passed originally addressed two areas of concern: 1) schools and day care centers, and 2) drinking water coolers. Schools and day care centers were targeted because of the children, and because the health effects of lead poisoning on children are well known (6). Day care homes were not mentioned in the Act, but these homes are just as important as day care centers from the standpoint of exposing children to lead. Drinking water coolers were targeted because some models were believed to have lead lined tanks or were believed to have other components in them made of lead (7). Outlets other than water coolers were not addressed in the LCCA, but these outlets are equally as important, because they are connected to the distribution system with lead solder joints, and some of them contain components made of lead just like the water coolers. Thus, outlets like icemaking machines, non-cooled water fountains, and classroom and kitchen sinks are potentially just as hazardous as drinking water coolers.
Under the LCCA of 1988, states were required to develop programs to assist schools and day care centers in identifying potential lead contamination problems in their drinking water and to assist them in remedying any such identified problems. In Missouri, a two part approach was used. The first part consisted of sending information to the schools and day care centers on how to assess their buildings for lead, and on how to get their water tested for lead. For the latter, a list of commercial laboratories in Missouri and some in neighboring states was supplied to all schools and day care centers. For the assessments, the EPA Manual entitled "Lead in School Drinking Water" was used (8). Even though testing was not required under the Act it was encouraged, since testing was the only sure way of determining which drinking water outlets were at risk.
The other part of Missouri's program consisted of a request that the schools and day care centers report back to the Bureau of Environmental Epidemiology with the results of their assessments, as well as the results of any testing that was done. The request also included a statement regarding the type of action taken to reduce the hazard from those outlets that tested above the action level of 20 parts per billion. Computer generated survey forms on which to record this data were furnished by the Bureau for the convenience of the schools and day care centers.
Table 1 Summary of responses from schools and day care centers to Missouri's program under the LCCA Public Day School Care Districts Centers Other(*) Number in Missouri, in 1990 528 1123 664 Percent responding to survey 49.6% 25.9% 20.3% Percent having water coolers 49.4% 8.2% 17.5% Percent testing for lead 28.5% 7.5% 8.4% * Private and parochial schools. Table 2 Summary of testing results for lead in drinking water coolers Public Day School Care Districts Centers Other(*) Drinking water coolers 2990 106 236 |is less than~5 ppb 75.1% 76.4% 79.7% 5 - 10 ppb 15.6% 13.2% 14.8% 11 - 20 ppb 5.6% 5.7% 2.5% |is greater than~20 ppb 3.7% 4.7% 3.0% * Private and parochial schools
Results and discussion
The response to the program by the schools and the day care centers in Missouri was very good, considering that the Act did not require them to either test for lead or even respond to the program. The results of these responses are summarized in Table 1 and are discussed briefly below.
* Of the 528 public school districts in Missouri, 49.6% of them responded to the program; that is, the survey forms were completed and sent back to the Bureau of Environmental Epidemiology.
* Of the 528 districts, 28.5% of them tested their drinking water outlets for lead.
* Of the 664 "other" schools (individual private and parochial), 20.3% responded to the program, and 8.4% of the 664 schools tested their outlets for lead.
* Of the approximately 1,123 day care centers in Missouri, 25.9% of them responded to the program, and 7.5% of the total number had tested for lead.
* Of all the schools responding to the program, 94.9% reported having water coolers (cooled-type fountains); whereas only 31.6% of the reporting day care centers had coolers. This difference was not unexpected as many if not most of the latter take water for drinking from the kitchen sink.
The testing results reported to us on the survey forms were analyzed by type of outlet from which water was taken and by the amount of lead found in the water. Tables 2,3, and 4 give a detailed breakdown of testing results by type of outlet and for each of the public school districts, day care centers, and "other" (private and parochial) schools. For the public schools, results were analyzed by district instead of the individual schools within the district. Table 5 is a summary by type of outlet combining the results of all the districts, day care centers, and private and parochial schools. A summary of the combined results is discussed briefly below.
* Of the 3,332 drinking water coolers tested, only 3.7% of them tested above the 20 ppb action level recommended under the LCCA; 75.4% of them tested less than 5 ppb.
* Of the 846 non-cooled drinking water fountains tested, 4.6% tested above 20 ppb, and 64.1% of them tested below 5 ppb.
* Classroom and kitchen sinks and ice making machines were lumped together for this summary. Of the 2,596 tested, 7.6% of them were above the action level of 20 ppb, and 61.3% tested less than 5 ppb.
Other analyses of the data indicate that of all the outlets tested in the schools (districts, private, and parochial), 5.5% of them tested above the 20 ppb action level recommended under the LCCA, and in the day care centers 2.4% exceeded this action level. Further analysis found that 8.3% of the sinks and ice making machines in the public school districts tested above 20 ppb; whereas, only 1.6% of the sinks in the day care centers exceeded this level.
The amount of testing done by the schools and day care centers varied considerably. For example, in some schools and day care centers all of the outlets used for drinking were tested for lead contamination. In others, only water coolers were tested, and in some only a few outlets which were considered representative of the whole school were chosen. In some cases the schools and day care centers collected all the water samples themselves and sent them to the testing laboratory for analysis, according to directions from either the Bureau of Environmental Epidemiology or from the laboratory. Others contracted directly with a laboratory or with an environmental consulting firm to do both the sampling and the analysis.
For those outlets in both the schools and day care centers that exceeded the level of 20 ppb recommended by the LCCA, action was taken immediately in most if not all cases to reduce the hazard. Remediation measures consisted of flushing, replacing the outlets, or taking the outlets out of service.
The results of this state-wide survey were compared with the testing results from a single large school district in central Missouri. The comparison was made because this particular district tested all the outlets in the school and each outlet was identified accurately as to type; that is, it was identified as either a drinking water cooler, a non-cooled drinking water fountain, a kitchen/cafeteria or classroom sink or an icemaking machine. This comparison was made in part because the fountains inventoried on the survey forms from some schools were, in some cases, not always accurately described as cooled or non-cooled.
The results from this school district are presented in Table 6, and are summarized here. Of the 205 drinking water coolers, 3.4% of them tested above 20 ppb. Of the "other" (kitchen/cafeteria/classroom sinks, icemaking machines, etc.) type outlets tested, 10% were above the action level. None of the non-cooled fountains tested above 20 ppb. Thus, the results of this one school district compared favorably with the results of the state-wide survey.
The results of this program survey indicate that the drinking water being dispensed from most of the outlets in the schools and day care centers in Missouri is safe to drink from the standpoint of exposing children to lead. Those schools and day care centers that tested for lead and had outlets exceeding the action level took steps to reduce the hazard as soon as possible in most cases. However, since most of the schools and day care centers have yet to test their water, there are still outlets in those schools and day care centers that are posing a risk to the children using them.
Table 3 Summary of testing results for lead in drinking water fountains Public Day School Care Districts Centers Other(*) Fountains (non-cooled) 719 62 65 |is less than~5 ppb 62.2% 77.4% 72.3% 5 - 10 ppb 22.3% 25.0% 16.9% 11 - 20 ppb 11.5% 2.0% 7.7% |is less than~20 5.0% 2.0% 3.1% * Private and parochial schools. Table 4 Summary of testing results for lead in sinks and icemaking machines Public Day School Care Districts Centers Other(*) Sinks, icemakers, etc. 2257 244 96 |is less than~5 ppb 60.4% 67.2% 66.7% 5 - 10 ppb 21.4% 22.5% 17.7% 11 - 20 ppb 9.9% 8.6% 10.4% |is greater than~20 ppb 8.3% 1.6% 5.2% * Private and parochial schools.
Richard H. Gnaedinger, Ph.D., Environmental Specialist, Bureau of Environmental Epidemiology, Missouri Department of Health, 1730 East Elm St., Jefferson City, MO 65101.
1. Subramanian, K.S. and J.W. Connor (1991), Lead Contamination of Drinking Water, J. Environ. Health 54 (2):29-32.
2. U.S. Environmental Protection Agency (1988), The Lead Contamination Control Act, 42 U.S.C. 201 and 300j, Sections 1461- 1465.
3. U.S. Environmental Protection Agency, National Interim Primary Drinking Water Regulations (1974), 40 CFR 141 and 143.
4. U.S. Environmental Protection Agency (1991), National Primary Drinking Water Regulations for Lead and Copper, 40 CFR, Part 141.
5. U.S. Department of Health and Human Services (1991), Preventing Lead Poisoning in Young Children, A Statement by the Centers for Disease Control, 105 pages.
6. Martin, D. (1991), Lead Poisoning in Children, J. Environ. Health 54 (1):18-19.
7. U.S. Environmental Protection Agency (1989), Drinking Water Coolers That Are Not Lead Free, Federal Register 54 (67):14320-14322.
8. U.S. Environmental Protection Agency (1989), Lead in School Drinking Water, #055-000-00281-9, Superintendent of Documents, U.S. GovernmentPrinting Office, Washington D.C. 20402-9325.
9. Taylor, R. (1990), Heavy Metal, Heavy Toll: The Lasting Legacy of Low Level Lead in Children, The J. of NIH Research 2:57-60.
Table 5 Summary of testing results by type of outlet Drinking water coolers 3332 |is less than~5 ppb 75.4% 5 - 10 ppb 14.0% 11 - 20 ppb 5.0% |is greater than~20 ppb 3.7% Fountains (non-cooled) 846 |is less than~5 ppb 64.1% 5 - 10 ppb 18.1% 11 - 20 ppb 9.8% |is greater than~20 ppb 4.6% Sinks, icemakers, etc. 2596 |is less than~5 ppb 61.3% 5 - 10 ppb 18.5% 11 - 20 ppb 8.6% |is greater than~20 ppb 7.6% Table 6 Summary of test results from a large central Missouri school district Drinking water coolers 205 |is less than~5 ppb 81.0% 5 - 10 ppb 12.2% 11 - 20 ppb 3.4% |is greater than~20 ppb 3.4% Fountains (non-cooled) 3 |is less than~5 ppb 0.0% 5 - 10 ppb 66.7% 11 - 20 ppb 33.3% |is greater than~20 ppb 0.0% Other outlets (*) 349 |is less than~5 ppb 62.5% 5 - 10 ppb 17.8% 11 - 20 ppb 9.7% |is greater than~20 ppb 10.0% * Kitchen/cafeteria/classroom sinks, icemaking machines, etc.
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|Author:||Gnaedinger, Richard H.|
|Publication:||Journal of Environmental Health|
|Date:||Apr 1, 1993|
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