Lead is a metal that has many commercial uses. Nearly everyday you can be exposed to trace amounts of lead through air, soil, household dust, food, drinking water and various consumer products. Human activities release more lead in the environment than natural processes. Drinking water is not generally the most significant source of exposure to lead yet under certain conditions lead can leach into drinking water through the process known as corrosion.
According to the EPA in 40 CFR Parts 9, 141 and 142, lead is considered a chronic contaminant that impairs and damages the nervous system and other systems after extended periods of exposure. Lead toxicity is believed to be a function of repeated exposures over time that results in a gradual accumulation of lead in the soft tissues and the skeleton.
Short and Long-Term Effects
Lead has the potential to cause a variety of adverse health effects when people are exposed at levels above the drinking water action level or within a short time period. These effects may include:
— Interference with red blood cell chemistry
— Delays in normal physical and mental development in babies and young children
— Slight deficits in the attention span
— Interference with hearing and learning abilities of children
— Slight increases in the blood pressure of adults
Lead has the potential to cause the following effects from a lifetime exposure at levels above the action level: stroke, kidney disease and cancer. Young children, infants, and fetuses appear to be particularly vulnerable to lead impacts as they more rapidly absorb any lead they consume. In infants, whose diets consist of liquids made with water, such as baby formula, lead in drinking water constitutes an even greater proportion of total lead exposure.
Sources of Lead
Lead may occur in drinking water either by contamination of the water in the municipal water system or by corrosion of lead plumbing or fixtures. Corrosion of plumbing is by far the greatest cause for concern. All water is corrosive to metal plumbing materials to some degree. Overtime, lead-containing plumbing materials will usually develop a scale that minimizes further corrosion of the pipe.
Lead in drinking water is most often a problem in buildings that are either very old or very new. Up through the early 1900s, it was common in some areas of the country, to use lead pipes for interior plumbing. Also, lead piping was often used for the service connections that join the buildings’ plumbing systems to public water supplies. Unfortunately this practice ended only recently in some localities. Plumbing installed before 1930 is most likely to contain lead. Copper pipes have replaced lead pipes in most residential plumbing. However, the use of lead solder with copper pipes is widespread. Experts regard this lead solder as the major cause of lead contamination of household water in homes today. New brass faucets and fittings can also leach lead, even though they are “lead-free”. Scientific data indicates that the newer the home, the greater the risk of lead contamination. Lead levels decrease when a building ages as mineral deposits form a coating on the inside of the pipes, if the water is not corrosive, and isolates the water from the solder. But, during the first five years, water is in direct contact with the lead. Water in buildings less than five years old is more likely to have higher levels of lead contamination (Actions You Can Take to Reduce Lead in Drinking Water, EPA 2006).
Brass-containing faucets and submersible pumps
Brass is also found in faucets and submersible well pumps. As the water sits in brass faucets, lead may leach into the water in excess of the EPA action level of 15ppb (parts per billion). There are approximately 12 million water wells that are equipped with brass-bearing submersible pumps. Recent studies have demonstrated that the lead level in well water standing in contact with brass for eight hours increased as much as 20 fold. Under these conditions, the lead levels sometimes exceeded 50ppb. Although EPA regulations of 1986 limit lead in brass faucets to 8%, this regulation does not apply to submersible well pumps. (www.LeadCheck.Com )
Lead levels in drinking water are likely to be highest if:
— The building has faucets or fittings of brass which contain some lead. or
— The building or water system has lead pipes, or
— The building has copper pipes with solder, and
— is less than 5 years old
— has naturally soft water and
— water often sits in the pipes for several hours
Regulations
The EPA establishes drinking water quality standards. The Maximum Contaminant Level Goal (MCLG) for lead in drinking water is zero; however, this is a non-enforceable health goal. The Maximum Contaminant Level (MCL), an enforceable standard, for lead in drinking water is established as an Action Level of 0.015 mg/L or 15 parts per billion (ppb). An Action Level is defined as the concentration of a contaminant which, if exceeded, triggers treatment or other requirements that a water system must follow.
The National Primary Drinking Water Regulations for Lead and Copper in 40 CFR 141, also called the Lead and Copper Rule, became effective in 1991. Among other things, it established treatment technique requirements and public education programs. These requirements may be triggered if more than 10 percent of tap water samples collected during any monitoring period exceed the lead action level (0.015 mg/L) and/or the copper action level (1 .3 mg/L).
Sampling
Sampling requirements apply, depending on whether the public water system is classified as a "community water system” or a “non-community water system.” The sampling requirements for public water systems are based on the number they serve. For information on the requirements for a specific public water system, public water system owners should reference, Lead and Copper Rule: A Quick Reference Guide, EPA 2004, and check with the local health department and their state agency to determine specific requirements.
If lead is suspected or detected in drinking water, the property owner has many resources available to evaluate the situation: the state or local environmental agency, the municipal water provider, and environmental professionals that specialize in lead and drinking water quality.
In addition, many state and local health departments or state agencies require drinking water or private well registration and/or additional monitoring. Well owners may contact the local health department and state agency to determine their specific requirements.
Conclusion
The presence of lead in drinking water need not create panic. Instead, owners of industrial/commercial or residential properties, and owners and operators of public water systems should check with local and state regulations for rules and guidelines in the management of lead in drinking water in order to prevent potential problematic exposures and liabilities. Sampling should be conducted according to any required schedules and controls should be implemented as necessary to maintain water quality.
Property owners and private well operators who have knowledge of water supply sources, classifications, sampling requirements and treatment options, will be better prepared to implement a risk management program that reduces the potential for third-party insurance claims.
Your water provider should include a copy of water tests results annually in your bill.
You should also be able to request them at no charge, or check their website to see if they are posted.
Resources
National Primary Drinking Water Regulations for Lead and Copper; Final Rule, Code of Federal Regulations, (40 CFR Parts 9, 141 and 142)
Consumer Factsheet on Lead in Drinking Water, EPA, 2006 (www.epagov/safewater/lcrmr/fs_consumer.html )
Actions You Can Take to Reduce Lead in Drinking Water, EPA, 2006 (www.epa.gov/safewater/lead/lead1.html )
Revisions to the Regulations Controlling Lead in Drinking Water: Fact sheet, EPA, 2006 (http://www.epa.gov/ogwdw000/lcrmr/pdfs/2006_Proposed_Rule_Revisions_Fact_Sheet.pdf )
Commonly Asked Questions: Section 1417 of the Safe Drinking Water Act and the NSF Standard, EPA, 2006, (www.epa.gov/safewater/lcrmr/lead_nsfstandard.html )
Lead and Copper Rule: A Quick Reference Guide, EPA 2004 (www.epa.gov/safewater.html )
2006 Edition of the Drinking Water Standards and Health Advisories EPA 822-R-06-01 3, Office of Water, EPA, August 2006 http://www.epa.gov/waterscience/criteria!drinking/dwstandards.pdf
