Wastewater Treatment: HVSSD Septic Lagoon Odor Control

Background

Heber Valley Special Services District (HVSSD) operates a multiple lagoon wastewater treatment system that receives raw sewage from Heber City and the City of Midway, Utah and discharges treated wastewater to farmland.

The Challenge

HVSSD has received lagoon odor complaints from high-end residential neighbors in the past. Plans to construct additional high-end housing near the lagoons have increased the pressure on HVSSD to assure odor abatement.

ERG’s Solution

ERG conducted lagoon sampling investigations and evaluations during Fall 2023 to determine potential causes of odor generation and develop odor mitigation solutions prior to the upcoming Spring turnover when the bottom layer rises to the top causing floating sludge and noxious odors. ERG installed a system to inject hydrogen peroxide near the raw sewage discharge point to quickly oxidize hydrogen sulfide where thick sludge accumulates and nearby aerators are inoperable. Calcium nitrate was injected at an upgradient lagoon location to provide slow-release oxygen for the biological degradation of dissolved sulfide. A second hydrogen peroxide injection system was installed at the inlet works of a separate lagoon prior discharge of raw sewage into the lagoon.

Client Results

• No lagoon odors were reported during Spring turnover.

 SERVICES PROVIDED

Remediation system installation • Sampling • System design