Project Description

As one of the fastest growing cities in Arkansas, it is a challenge for Bentonville to keep pace with expanding infrastructure needs. The city entrusted the growth of its water resource recovery facilities to HW. A feasibility study concluded there was a clear financial advantage for expanding the capacity of the city’s existing WRRF as opposed to pumping more flow to a regional treatment plant. The WRRF is tucked between the bottom of a hill and Town Branch Creek, just upstream of the Crystal Bridges Museum and surrounded by walking trails. There is no room to expand the size of the existing plant. Even when space constraints are not as severe, utilities are often challenged to do more with their existing infrastructure due to high material and construction costs. This innovative project increased the capacity of the WRRF by enhancing the existing basins to support the needs of double the population of microorganisms and to select for the most efficient types. With more and better microorganisms, the WRRF can provide the treatment capacity demanded by the growing city. This project also included screening, advanced grit removal, MLSS selectors, biological nutrient removal, advanced phosphorus removal, innovative clarification, parallel filtration, ultraviolet disinfection, effluent pumping, and architectural improvements.