Marana Water News: WQ-What?

Ever wonder how a sewer bill is calculated? We don’t install meters for the outflow from our customer’s homes, so we use an industry standard estimate called a Winter Quarter Average (WQA). This week, we will share how this is calculated, and how it may affect your next water bill.

Most entities that provide sewer service do not install a meter on the flows into the sewer. However, we do know that many of our customers use water for irrigation or filling pools and water balloons, which means this usage would not get into the sewer system. In order to calculate the contribution to the sewer for each account, we use the WQA.

Our WQA is based on the usage for our customers during the previous December, January, and February. These months are typically the lowest usage months since we do not tend to use water outside as much during the winter months. We infer that this is the best measurement of the water used inside that would enter the sewer through dishwashers, showers, toilets, and other household uses. This allows us to provide as accurate a consumption measurement as possible.

Each July, this WQA is updated. We will calculate the average for those three winter months, and then use that to determine what each monthly sewer bill will be for the next year. When filling pools or washing cars we want you to be sure to keep these months in mind to maintain an accurate winter average. When it comes time for billing each month, we will review the monthly water consumption that was picked up from the meter reading and the WQA. Your bill will reflect whichever of these two values is lower. See the example below for how a sewer bill is calculated. Please note that Pima County Regional Water Reclamation Department now has different rates that Marana Water for sewer charges. The example shows the Marana Water rates on a sample water bill.  Since we use this average, many of our customers may see the sewer charges be exactly the same each month. That WQA is a stop-gap measure should you have any unintentional water use at the property. The WQA is the highest consumption value that a customer would pay in a given month.

The bill that our customers will receive in the next few weeks will now be calculated with these new averages. Should you see a change in the sewer charges portion of your bill, the culprit is likely your WQA. If you would like to read more about our water reclamation division, click here. As always, we are happy to review a statement with you, just give our office a call at (520) 382-2570.


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