How to Identify Your Service Line Material

Identifying the material of a service line can be challenging: local plumbing codes vary and different pipe material and fittings were used during different decades. The materials available today were not necessarily available decades ago. One approach to identifying the material is to physically inspect the piping. Service line pipes may be exposed where they enter the home through a basement wall or floor, at the water meter, or when discovered through excavating the dirt over the service line or where it connects to the water main. 

This illustration shows a common arrangement where the water system (Portsmouth utility) and the property owner (customer) each own the part of the service line that supplies water to the property. The actual arrangement can differ across places (Federal Reserve Bank of Chicago, 2022).


Locating your Water Service Line

From the basement of your property, walk the perimeter of the floor to locate your water meter. There may be a cap on this meter that covers the dial plate associated with the volume of water that has entered your home. There will be arrows on the top side of the meter, indicating the direction of flow from the water main outside of your building, flowing inward to your internal plumbing. Trace the pipe from the water meter backwards in the direction of your basement floor or cement wall. This section of pipe entering your foundation is your water service line (see below).

Visual Scratch Testing

Using a hard, metal object such as a key or screwdriver, you should be able to confirm the pipe material entering your home by physically scratching the service line. Using a magnet, you can determine if your service line is made of galvanized iron/steel if the magnet clings to the pipe. Lead is a dull gray color and very soft. If scraped with a key it will turn a bright silver color. Even a very strong magnet will not stick to lead. Look for these signs below to accurately identify your water service material:

Source: DC Water

Service line identification tutorial provided by NY Department of Health.

Once you have successfully located your service line and understand the process of material identification via scratch-testing, please fill-out the form below to notify the Portsmouth Water Division. This contribution to our inventory efforts is greatly appreciated and will help the Water Division meet new federal requirements while providing further insight into our ongoing service line replacement plan.