NACA WWTP Expansion

Evaluating processes to meet future nutrient limits

In 2010, the Northwest Arkansas Conservation Authority (NACA) opened a new, state-of-the-art $65 million wastewater treatment plant (WWTP) with an average treatment capacity of 3.6 MGD and a wet weather peak flow capacity of 13.5 MGD. NACA hired Garver to develop the conceptual design for the first expansion of the WWTP, which helped maintain adequate treatment capacity to meet the needs of Northwest Arkansas’s growing population. The planned capital improvements included modification, refurbishment, and expansion of existing facilities to increase liquid treatment process capacity average day flow rate from 3.6 to 7.2 MGD. As part of the conceptual design, Garver also assisted with obtaining funding through the Arkansas Natural Resource Commission’s (ANRC) Clean Water Revolving Loan Fund (CWRLF). This process included preparing and submitting a categorical exclusion through the ANRC, leading the development of the National Pollutant Discharge Elimination System (NPDES) permit renewal, and performing field surveys using radial topography methods.