With funding from the California Energy Commission and input from CEE’s Water/Wastewater Committee, the American Water Works Association Research Foundation (AwwaRF) is developing a metric to measure energy usage in water and wastewater facilities.

This metric will assess the effectiveness of internal energy management systems and make energy use among different water and wastewater facilities comparable.

To gather the necessary data, AwwaRF recently completed a nationwide survey of facility energy use. The survey addressed key characteristics of water production, treatment and distribution for water utilities and collection and treatment for wastewater plants.

Thus far, AwwaRF has received completed surveys from 367 wastewater treatment facilities and 217 water treatment facilities.

CEE, ENERGY STAR^®, and the water and wastewater industries see potential benefit in incorporating the metric into a facility energy performance benchmarking tool, similar to the one developed by ENERGY STAR for commercial buildings.

Having completed the survey, Steve Carlson of CDH Energy, has developed draft formulations for the water and wastewater benchmark metrics based on the best regression models.

The wastewater model is based on the following parameters: flow, Biochemical Oxygen Demand (BOD), load factor, presence of trickle filtration and presence of nutrient removal.

The water model is based on the following parameters: total flow, purchased flow, total pumping horsepower, as well as horsepower for source/raw water and distribution, BOD, and main length.

The formulations above were used to identify the highest and lowest scores among the participating water utilities for further investigation, essentially determining a metric benchmark ranking scale.

Carlson is currently compiling utility-specific summaries for comment by the participating utilities and selected utilities based on source energy, model calculation and energy use range of scores.

The summaries will include a brief overview of the sample data (number of utilities, range in energy use parameters and frequency of some key operating characteristics).

In addition, Carlson is developing case studies on the results and impressions of water utility members in applying the metric to their situations.

The Water/Wastewater Committee is continuing to monitor this project as it develops and will provide ongoing input from a program implementation perspective.

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