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.