Security Sanitation District

The Security Sanitation District (SSD) has operated a wastewater treatment facility since the 1950’s.  Improvements and modifications have been made to this facility since it became operational with the most significant improvements occurring in 1987.  The facility’s discharge permit contains new numeric effluent limits for total inorganic nitrogen, ammonia, phosphorus, copper, zinc and cyanide.

The current treatment process was not able to meet these new limits, thus requiring new treatment components.  GMS, Inc. designed and provided construction oversight for the improvements to the WWTF.  The secondary treatment process was changed, and with these changes, various other improvements to the facility were implemented.

The headworks facilities have been upgraded with a new mechanical screen, screening compactor and washer, and a new grit removal system. The new IFAS (Integrated Fixed Film Activated Sludge) system has multiple process trains for reliability and operations flexibility. This IFAS system will enable SSD to meet the effluent limit for ammonia, total inorganic nitrogen, copper, zinc and cyanide.  Traditional secondary clarifiers follow the IFAS system. An additional treatment component is the sludge handling system to manage the solids for WAS thickening.  In the final treatment step prior to discharge, improvements were made to the existing ultraviolet radiation disinfection system.

Biosolids stabilization remains with the existing anaerobic digestion process; however, improvements to the sludge handling equipment were made. A new dewatering process was incorporated following the sludge stabilization.