Sni-A-Bar Creek Water Quality Study: Development of Site-Specific Criteria, Wasteload Allocations and Antidegradation Review

The City of Blue Springs is expanding their current wastewater treatment plant (WWTP), which discharges into Sni-A-Bar Creek, from 6 to 10 mgd to accommodate growing wastewater needs as development progresses around the Kansas City metropolitan area. Perennial reaches of Sni- A-Bar Creek are included in Missouri's impaired waters list due to low dissolved oxygen (DO) concentrations. Geosyntec (formerly MEC Water Resources) and agency scientists believed that Sni-A-Bar Creek did not attain the statewide DO criterion naturally during summer conditions due to shallow depths, high residual sediment oxygen demand, and low reaeration. State regulatory policies require intensive water quality study and evaluation of attainable conditions to permit WWTP expansions within impaired reaches. Study efforts resulted in gaining the first state regulatory approval of site-specific criteria by rulemaking in 2009, as well as approval of water quality-based effluent limitations based upon attaining these site-specific criteria.