Reducing Lead Exposure Through Drinking Water
By: Steven Lambert | Jun 02, 2021
There is no safe level of lead in drinking water, but a zero goal, though laudable, is at present an unattainable goal. The policing of lead in drinking water is generally in the hands of the local utility company until testing reveals lead levels higher than 15 ppb (parts per billion) in 10% of the samples collected in the distribution system. This means the action level for remedial action is 15 ppb. The frequency and number of samples collected is determined by the service population of the utility, history of analysis results, and the success of remedial measures, if they prove to be required. Remedial measures may be avoided by implementing some measures as ongoing treatment regimens, whether there is a problem or not. The chief remedial or preventive actions involve implementing and maintaining a corrosion control program to prevent leaching of regulated metals, such as lead and copper, into the product.
As stated before, there are certain remedial actions that can be taken when 15 ppb is exceeded. Corrosion control, including keeping the finished product at an alkaline pH (above 7.0 pH) and treatment with anti-corrosives, usually sodium phosphates, should be practiced. Acid pH levels (below 7.0 pH) create a corrosive environment causing metals to leach into the water, thus the need to maintain an alkaline pH. The use of anti-corrosives will interfere with the electromagnetic action that causes corrosion when pH controls are not enough, which is nearly always.
At best, the chief approach should be the elimination of the lead sources, whenever possible. Lead service pipe in aging systems should obviously be replaced. Non-lead pipe may still introduce lead via old lead seals between adjoining lengths of pipe. Removal of non-lead pipe is a daunting and expensive task for most utilities and these utility providers can usually comply with the treatment methods already discussed. A constant vigil of following an approved Lead and Copper Sampling Plan and required analysis must be maintained by all systems by law.
The most notable example of lead control failure by utilities is the Flint, Michigan debacle that exposed its residents to high levels of lead as a result of money saving measures after the utility came under direct control of State managers. In short, the entire episode may have been avoided by providing proper treatment to prevent corrosion.
Facilities such as schools or daycare facilities are particularly vulnerable due to periods of downtime during weekends, holiday breaks, and summer vacations. Standing water in the pipes can corrode sources of lead, allowing leaching. Copper pipes joined by lead solder, aging plumbing fixtures, water fountains, and lead piping are all vulnerable to corrosion and leaching.
There is no federal requirement for schools and similar facilities to sample and test for lead. Some states have taken action by making this a requirement. Other states press for voluntary efforts. The U.S. Environmental Protection Agency (EPA) also encourages voluntary action and has provided $40,000,000.00 to aid in funding of this effort.
The EPA has developed a “Tool Kit” for facilities to use as a guide for successful programs. Stressed here is adherence to the “Three T’s:” Training, Testing, and Taking Action. This information is provided to instruct personnel on how to achieve reduction in lead contamination.
Three T’s
TRAINING involves methods for sampling and submitting samples for analyses. All staff should be included in the training of methods they may use to reduce lead contamination at all employment levels. The proper method for sampling involves following the provided instructions in the sampling “kit.” Training must be provided on how to follow these instructions and provide for delivery of the sample(s) for analysis. The utility staff is a good source of information for this.
TESTING is the analysis of the sample(s) by a certified laboratory. The collector will take the sample and complete their portion of the paperwork provided. The facility may wish to transport the sample(s) directly or avail themselves of the pickup services provided by the laboratory. Several samples in different areas of the facility will be required in order to isolate problem areas. Once completed, any problem area should be subdivided, sampled, and tested to better pinpoint the offending plumbing or fixture(s).
TAKING ACTION is any action required to eliminate the contamination. This is mostly achieved by complete replacement of offending pipes and/or fixtures and repeat sampling and analysis of water in the formerly offending pipes and/or fixtures. A good result is proof the action taken was successful. Informing the public of the action taken must be a part of taking action.
