Wastewater Facility Plan & Ground Water Monitoring - Kendrick, ID

The City of Kendrick has experienced excessive wastewater flows during the wet weather months due to inflow and infiltration (I/I) into their collection system. The I/I resulted in a number of discharge permit violations from their lagoon wastewater treatment system. An additional hurdle the City is facing relates to lagoon seepage testing. The lagoons were tested and found to be leaking above the allowable regulatory limits.

Mountain Waterworks was hired by the City to complete a wastewater facility plan to resolve their I/I issues, determine upgrades necessary to mitigate permit violations, and long-term recommendations to meet future permit conditions. To assess the collection system pipelines and manholes, Mountain Waterworks coordinated hydro cleaning and video inspection for the majority of the system. Each manhole was also visually inspected in the field to determine necessary repairs.

For the wastewater treatment system, a lagoon seepage analysis was conducted to evaluate the environmental impacts of the lagoons. Shallow groundwater wells were constructed and samples drawn, along with surface water sampling upstream and downstream of the lagoons, to assess lagoon seepage. The testing results show no significant impact to the environment which may allow the facility to remain in service without costly repairs. Considering future permit considerations, the City is evaluating rapid infiltration wastewater disposal as the most economic discharge alternative. Continued discharge to the Potlatch River will require significant wastewater treatment upgrades which will be difficult for the community to pay for, operate, and maintain.

The overall goal is to minimize the upfront capital costs, along with long-term operation and maintenance expenses of the system; while economically addressing the issues necessary to meet current and future regulatory requirements.