Outfall 40 at HSAAP

Holston Army Ammunition Plant (HSAAP) is a Government-Owned, Contractor-Operated (GOCO) explosives production facility located in Kingsport, Tennessee. All production at HSAAP depends on river water.

The HSAAP river water system was installed in the early 1940s and was originally designed for resiliency and sustainability; but the system has degraded over time.Due to temperature compliance issues, all the production channels and outfalls to the Arnott Branch have been directed to Channel 1976 and associated Outfall 40. Approximately 970 acres of the HSAAP site now feed into Outfall 40 from a storm run-off standpoint; however, 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.

With planned increases in production and cooling water flow, this channel and outfall will exceed permissible temperature impacts to the Arnott Branch as required by operation permits. The Project includes modifications to Outfall 40, which involves re-routing and channel improvements. Improvements include 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.

Construction of the new channel will include a 10-foot clearing on either side for maintenance and construction, along with a temporary road and turnaround on the eastern side for construction vehicles.Please see the attached document for further details