Understanding Your Water Meter

Water Meter An example of a water meter from our warehouse.

What is a Water Meter?

A water meter is a device used to measure the volume of water used on your property. PWSA uses these readings for billing purposes, but it also allows customers to monitor their water usage. 

Learn more about your water meter, how it tracks daily water usage, and ensures accurate readings by clicking through the questions below. 

Common Questions About Water Meters

How does my meter work?

Homes and businesses served by the Pittsburgh Water and Sewer Authority (PWSA) are equipped with a water meter that tracks daily water usage. As water flows into the meter body, it enters the measuring chamber. The motion of the water causes the measuring element (known as the nutating disc) to rotate. Throughout the day, the disc counts off the number of rotations to register your water usage. This data is transmitted remotely multiple times per day to our automated meter reading system and is used to generate each customer’s monthly PGH2O bill.

How accurate is my meter?

The American Water Works Association standardizes accuracy ranges for the entire water industry to ensure fair and accurate measurements. Each individual meter is tested, and the results of these tests are posted by the manufacturer before a meter is installed in a home or business. Meter accuracy is an element of the meter’s warranty. If tested out of range – meaning that the flow rate registers above or below the acceptable range for the meter’s size - it can be rejected and returned to the manufacture.

When PWSA receives a supply of water meters from the manufacturer, they are equipped with the manufacturer’s test tag showing the low and high range of water usage for that meter. PWSA is required to test 10% of all meters received by the manufacturer, and even if one of those meters should over-register, the entire batch of meters is returned to the manufacturer.

Can a meter over register?

It is very rare for a meter to over register. *Industry testing shows that meters are generally designed so that if they fail, they under-register a customer’s consumption, rather than over-register it.

*Yee, Michael D., Economic Analysis for Replacing Residential Meter. Journal of the American Water Works Association Volume 91, Issue 7. June 1999.  

Why do water meters usually not over-register?

The water meter functions like a measuring cup or bucket. Excess water cannot be measured. It is filled, measured, and then dumped before being filled again.

My water usage is higher than expected. What may cause this?

You may have a water leak or there may be a problem with your home plumbing. If your water usage seems high, a good step is to check the property for leaks. Our leak detection webpage is a great resource to understand where leaks may occur and provides tips to identify them. If you can’t find a leak, or you find a leak that you’re not able to repair on your own, your next step should be to call a professional plumber.  

You can also track your monthly water usage using our online Customer Advantage Portal. Using this free tool, you can track your real-time water usage and receive alerts when there is a spike in water usage as compared to your usage history or to thresholds that you set. Setting usage alerts can help you detect costly water leaks in your property. Visit our Check Your Water Usage page to learn more.

Which factors may cause my water meter to measure higher than usual usage?

  • A leak in your home may cause higher than average water bills.
  • Changes may occur when an old, worn meter is replaced by a new meter that more accurately measures water consumption.
  • A meter’s accuracy will reduce over time, but it does not fluctuate up and then back down over the course of a few months.

What are some other factors that may affect meter accuracy?

A variety of factors such as excessive wear, corrosion, or debris clogging the meter strainer may affect its accuracy. These factors are more likely to cause the meter to under-register; register less water than is consumed.

Where is my water meter located?

In most residential properties, water meters are either located along an exterior wall in the basement or in some cases are located outside in meter pits.   Water meters servicing businesses can be located in the lowest point of a building or in external meter vaults.

Who is responsible for maintaining the water meter?

PWSA owns, maintains, and operates all water meters that we install. The customer, however, is responsible for properly protecting the meter from damage by frost or other natural occurrences. To protect your water meter from cold or freezing temperatures, especially if it is located outside, wrap it in a towel or small blanket as you would to protect a pipe to keep it from freezing. If a meter is damaged due to negligence or intentional act, the customer is responsible for repairs or replacement. More information about customers’ water meter responsibilities can be found in our Water Tariff located on our Rules and Regulations page.