Outfall 40 at HSAAP

The project involves modifications to Outfall 40 at the Holston Army Ammunition Plant (HSAAP) in Kingsport, Tennessee. The HSAAP river water system was installed in the early 1940s, but it has degraded over time, and temperature compliance issues have directed all production channels and outfalls to Channel 1976 and associated Outfall 40. The project includes re-routing and channel improvements, such as the construction of a new portion of channel that discharges directly into the Holston River, channel stabilization, and the abandonment of the existing weir and Outfall 40 into Arnott Branch. • The project requires the construction of a new channel with a 10-foot clearing on either side for maintenance and construction. • A temporary road and turnaround on the eastern side will be built for construction vehicles. • The majority of flow in this channel and outfall is from once-through non-contact cooling water (NCCW) discharging from various production facilities on the site. • The project aims to address temperature compliance issues and prevent excessive temperature impacts to the Arnott Branch.