Sampling Plan:

Testing for lead and copper is done a bit differently than for other contaminants. The sources are tested but generally do not contain significant levels of lead or copper. Typically these elements enter the drinking water through corrosion of home plumbing materials such as copper pipes, brass fittings and joint solders that contain lead. The level of contamination is dependent on the corrosivity of the water, the age of the plumbing materials and the amount of time the water is in contact with the plumbing. Originally, we were required to test 40 sites every six months and are now on a reduced annual sampling plan. We now collect twenty samples each year. The sampling sites are selected based on their degree of risk and their location in the distribution system.

Risk Assessment:

One of the major contributors to lead contamination is lead based solder used to seal joints in copper pipes. The use of lead solder on potable water systems was banned in Massachusetts on June 19, 1988. All of the test sites must have been built prior to the ban. Sites are divided into three tiers based on their expected risk. The first tier (highest risk) includes all single family structures that are served by a lead service line (lead is not used for service lines in Topsfield); and/or with copper pipes with lead solder installed after 1982 but before 1986; and/or with copper pipes with verified lead solder installed after 1985 but before June 19, 1988. The second tier includes all of the buildings that meet the Tier 1 material requirements but are not single family residences. Tier 3 sites (lowest risk) include single family structures with copper pipes and lead solder installed. before 1983.

Schools and Daycare Centers:

Lead contamination can be particulary harmful to children. Due to the detrimental health effects and the multiple sources of lead contamination in the environment (lead paint, etc.) schools and daycare centers are automatically added to the sampling plan.