DURHAM - Residents can go online to calculate how much their water and sewer bills will increase under the tiered rate system that goes into effect July 1.

Visit www.durhamnc.gov and plug in how much water you use per month. Here's how it works.

Take a look at your water bill (or this sample bill) and find the number under "consumption."

Plug that number into the calculator's consumption field and press the calculate button.

For instance, if you see a 12 under consumption, as in the sample bill, your monthly water and sewer bill will be $75.31.

Customers will pay higher rates as their water usage increases under the new system. The average customer will see their bill rise by about one-third.

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