Preventing Lead in Drinking Water

Protecting Customers

Metro Water Services takes our responsibility to protect customers from lead exposure and other contaminants seriously. We take every precaution to ensure that the water delivered to each customer is of the highest quality possible and meets all Federal and State drinking water standards.

Nashville’s drinking water does not contain lead when it leaves the treatment plants but tap water can accumulate trace amounts of lead through the corrosion of plumbing materials containing lead.

Prior to the mid 1950’s it was common for plumbers to use lead pipe for service lines to connect a residence to the public water main. Additionally, lead soldering was used on copper pipe until 1988 and brass fixtures may contain lead as well. Insufficient historic record keeping prevents us from knowing an exact number of lead service lines remaining in our system and the type of plumbing material and fixtures utilized within a private residence is unknown to us.

Fortunately, MWS has had an intense corrosion control program since 1992 to prevent the possibility of lead leaching into your water. In 1992, MWS began adding a blended phosphate solution to control corrosion in the water distribution system

The combination of ortho/poly phosphate is added to the finished water and reacts to inhibit corrosion of water mains; tie-up nuisance metals; and remove scale deposits in pipes by bonding to the walls of pipes and forming a protective barrier.

Following EPA and State guidelines, we regularly monitor drinking water in the distribution system for lead to determine the effectiveness of our corrosion control program. The EPA has set and action level for lead at 15 parts per billion or 0.015 mg/L (equivalent to approximately 15 seconds of time in 32 years).

Public Water Systems that provide optimal corrosion control treatment and system monitoring showing that lead levels are at or below the action level (15 ppb) qualify for reduced monitoring. Compliance is determined by comparing the 90th percentile of results.

Due to the proven success of our corrosion control program, in accordance with State and Federal regulation, Metro Water Services samples for lead every three years.

Analysis for lead is done from household taps and other locations throughout the distribution system where lead service lines exist or may be suspected based on system age. The sampling is done during the summer months when lead levels would be highest due to water temperature.

The highest calculated 90th percentile since Metro Water Service’s corrosion control program began was 10 ppb and these numbers continue to decline due to the build-up of corrosion inhibitors in the distribution system.

Lead Service Line Replacement Program

A water service line connects your home to the utility main. Prior to the mid 50's, these service lines were often made of lead. Lead service lines are generally a dull gray color and are very soft. You can identify them easily by carefully scratching with a key. If the pipe is made of lead, the area you've scratched will turn a bright silver color. Do not use a knife or other sharp instrument and take care not to cut or puncture a hole in the pipe. (Note: Galvanized piping can also be dull gray in color. A strong magnet will typically cling to galvanized pipes, but will not cling to lead pipes.) Lead service lines can be connected to the residential plumbing using solder and have a characteristic solder "bulb" at the end, a compression fitting, or other connector made of galvanized iron or brass/bronze.

If your home has a lead service line, it is likely that other sources of lead exist in the home as well. If you suspect your home has a lead service line, hire a licensed plumberto inspect your pipes or have water samples from your home analyzed for lead by a certified laboratory.

Whose responsibility is it to replace a lead service line?

Metro Water Services replaces their portion of lead service lines when found during construction or repair activities. Metro Water Services owns the service line from the water main to the meter. The property owner is responsible for the service line from the meter to the residence or building. Lead service lines on a customer’s property are not part of the public water system and are the responsibility of the property owner. Any work on the customer owned portion of the water service line is the responsibility of the property owner. Metro Water Services strongly advises that you contact a licensed plumber for any work on your service line.

What is the cost of replacing a lead service line?

Actual cost of replacement reflects a number of factors including the length of the service line, the technique used to install the new service line, and the built environment where the service line is located.

How many lead service lines remain in Nashville?

MWS stopped installing lead pipe in the mid 50's but insufficient historic record keeping prevents us from knowing an exact number of lead service lines remaining in our system. Lead pipe is replaced when found during repair or other construction activities. It is important to understand that a lead pipe is not the only potential source of lead in water. Homes built prior to 1988 with copper plumbing have the possibility of lead solder joints. Additionally, brass fixtures including faucets, valves and couplings can contain lead. Again, this is why our corrosion control program is in place.

Frequently Asked Questions (FAQs)

What is lead?

Lead is a naturally occurring metal that is harmful if inhaled or swallowed. Lead can be found in air, soil, dust, food, and water.

How can I be exposed to lead?

The most common source of lead exposure is from paint in homes and buildings built before 1978. Lead-based paint and lead-contaminated dust are the main sources of exposure for lead in U.S. children. Lead-based paints were banned for use in housing in 1978.

Although the main sources of exposure to lead are ingesting paint chips and inhaling dust, lead also can be found in some household plumbing materials and some water service lines. The Environmental Protection Agency estimates that 10 to 20 percent of human exposure to lead may come from lead in drinking water. Infants who consume mostly mixed formula can receive 40 to 60 percent of their exposure to lead from drinking water. Metro Water Services ceased using lead pipe around 1955.

What are the risks of lead exposure?

Although lead levels in blood in the United States has declined over the last 50 years, lead can cause a variety of adverse health effects when people are exposed to it. These effects may include increases in the blood pressure of some adults; delays in normal physical and mental development in babies and young children; and, deficits in the attention span, hearing, and learning abilities of children.

How does lead get into my drinking water?

Lead is rarely found naturally in our source water or in the treated water flowing through the distribution system. More commonly, lead leaches into water over time through corrosion—a dissolving or wearing away of metal caused by a chemical reaction between water and your plumbing. Lead can leach into water from lead pipes, copper pipes with lead solder, faucets or fittings made of brass. The amount of lead in your water depends on the types and amounts of minerals in the water, how long the water stays in the pipes, the water’s corrosivity, and water temperature. This is one example of why Metro Water Services add a safe corrosion resistant additive to finished drinking water to minimize these effects.

How will I know if my drinking water has lead in it?

Metro Water Services regularly tests the water at a selected number of lead service line locations. Customers residing in these homes are made aware of the results and they are also provided to the TN Department of Environment and Conservation, as required.

You can also have your water tested for lead by a certified laboratory. Since you cannot see, taste, or smell lead dissolved in water, testing is the only sure way of telling whether there are harmful quantities of lead in your drinking water.

Is my home at risk for lead plumbing?

The EPA defines potential-risk homes as follows:

• Homes with a lead service line that connects the water main (located under the street) to your home’s internal plumbing.
• Homes with copper pipe and lead solder built after 1982 and before 1988.
• Homes with lead pipes.

In 1986, Congress enacted the “lead ban,” which stated that not only public water systems, but also anyone else who intends to install or repair drinking water plumbing connected to a public water system, must use “lead free materials.” As a result, homes built in or after 1988 are far less likely to have lead solder.

How can I find out if my home has lead plumbing?

If you’re concerned your home plumbing may contain lead pipes (lead is a dull gray metal that is soft enough to be easily scratched with a house key) or if you see signs of corrosion (frequent leaks, rust-colored water), you may want to have your water tested by a state-certified laboratory. Testing is the only way to confirm if lead is present or absent. For more information on testing your water, you can call Metro Water Services at 615-862-4600 or contact a private certified laboratory.

Hotlines

• National Lead Information Center: 1-800-424-LEAD
• EPA’s Safe Drinking Water Hotline 1-800-426-4791