Tres Rios constructed wetlands: maximizing beneficial reuse while balancing demands of diverse stakeholder needs

Abstract

The effluent flows from the 91 st Avenue Wastewater Treatment Plant (WWTP) are a coveted and valuable water resource in the Phoenix area. The current effluent flows of 130-150 mgd are nearly fully allocated, providing cooling water to the Arizona Nuclear Power Project (ANPP) and supplying agricultural users in the Buckeye Irrigation District (BID). The Tres Rios flow regulating and overbank wetlands provide a second tier of reuse. Whilst conveying the effluent to downstream customers, the wetlands provide approximately 300 acres of rare and valuable wetland habitat. In addition, the wetlands will remove total residual chlorine naturally, and achieve advanced ammonia and total nitrogen removal. This paper provides a summary of the wetland design and discusses the challenges of operating a large scale constructed wetland. These include optimizing process control and vegetation maintenance to maintain habitat value and meet treatment objectives, balancing water requirements of the wetlands with downstream customers, controlling mosquitoes and other vectors, overcoming regulatory hurdles, and assessing the cost/benefits of the wetlands over mechanical treatment processes.

Daily flow intermittence in an effluent‐dependent river: Impacts of flow duration and recession rate on fish stranding

“…As urban growth and water use increase, and treatment technology becomes more common, effluent-dominated streams and their unnatural flow regimes will become more prevalent (Martí et al, 2009). Management options do exist for reducing effluent fluctuations and corresponding flow intermittence, including the use of retention basins and artificial wetlands prior to discharge into rivers (Brown et al, 2011). These options could help effluent releases better mimic the natural flow regimes that native fishes in arid regions depend upon (Arthington & Balcombe, 2011).…”

Cultivating effective utility-regulator relationships around innovation: Lessons from four case studies in the U.S. municipal wastewater sector

“…The Tres Rios Wetlands are an innovative part of a larger multi-benefit, multi-phase project implemented by the City of Phoenix (the City) and federal partners in order to improve water quality in local waterways, reduce flooding in neighboring communities, and restore riparian habitat [61]. Design and implementation of the project occurred over a period of almost two decades and involved a staged and iterative approach.…”