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Willard Spur Water Quality Study

In collaboration with stakeholders representing a wide variety of interests, the Utah Division of Water Quality (DWQ) is undertaking a water quality research program to determine the assimilative capacity of nutrients in the Willard Spur ecosystem of Great Salt Lake. The goal of the Willard Spur Water Quality Study is to determine appropriate and defensible modifications to Utah's water quality standards to ensure long-term protection of Willard Spur's aquatic life uses.


Perry and Willard cities completed construction in 2010 of $28 million in various sewer improvements including a new regional wastewater treatment facility to be managed jointly by the two cities through an interlocal agreement. In May 2010, as construction of the Perry/Willard Regional Wastewater Treatment Plant neared completion, DWQ public-noticed the UPDES permit for the discharge of treated effluent from the plant into the Willard Spur of Great Salt Lake. In response to this solicitation, Western Resource Advocates (WRA)—on behalf of the Utah Waterfowl Association—petitioned the Water Quality Board (WQB) to prohibit all wastewater discharges to Willard Spur or to alternatively reclassify Willard Spur to protect the wetlands and current uses of the water, resulting in DWQ temporarily withholding the UPDES discharge permit.

The WQB denied the petition but directed DWQ staff to develop a study design to establish defensible protections (i.e., site-specific numeric criteria, antidegradation protection classes, beneficial use changes) for the waterbody. In addition, DWQ was directed to work with stakeholders to identify a path forward to allow the Perry/Willard Regional Wastewater Treatment Plant to operate while the studies are underway, with reasonable assurances that the effluent will not harm the ecosystem.

DWQ subsequently used existing and available data to evaluate the risk of the discharge under several nutrient increase scenarios and provide recommendations for a path forward. Numerous assumptions were necessary to estimate future risk, due to limited data availability and time constraints. Nevertheless, these analyses suggested that nutrient concentrations had the potential to reach levels similar to other Great Salt Lake wetlands where nuisance algae blooms and deleterious effects on submerged aquatic vegetation have been observed. However, these studies also suggest that deleterious effects are unlikely over the first few years of plant operations, provided that phosphorous reductions are implemented.

As previously directed by the Board, DWQ is moving forward with a precautionary approach and has worked with the cities to implement phosphorus reductions within six months of operation of the plant. The UPDES permit was modified to reflect this change and was approved on February 22, 2011. The new treatment plant began its discharge to Willard Spur on March 7, 2011.

This approach will allow DWQ to avoid further delays in plant operations, provided that further legal challenges to the UPDES permit can be avoided. As a result, DWQ also has entered into a Memorandum of Understanding (MOU) with the Bear River Migratory Bird Refuge (Refuge), wherein DWQ agrees to conduct whatever studies are necessary to ensure the long-term protection of Willard Spur's designated uses. This MOU, coupled with securing the necessary funds to conduct these investigations, provides the Refuge and WRA with concrete assurances that monitoring is sufficient to identify unanticipated problems, and that DWQ is working with stakeholders to determine appropriate long-term protections for the Willard Spur ecosystem.

Please see this memorandum prepared for the Willard Spur Science Panel in August 2011 summarizing the project's background and providing a timeline and summary of supporting documents.


Willard Spur Study