Problem

The City of Seneca’s wastewater collection system faced significant issues that impacted its efficiency and compliance with environmental regulations. The existing infrastructure, relying on gravity-based systems and a single lift station, was plagued by seepage and inflow/infiltration (I&I) problems. Additionally, the outdated sewage lagoons required closure to meet the Oregon Department of Environmental Quality (DEQ) standards.

• • • Seepage Issues: The facultative wastewater treatment lagoons exceeded the allowable seepage limits set by the Oregon DEQ.
    • Inflow and Infiltration (I&I): The collection system experienced significant I&I, compromising the treatment and storage capacity.
    • Obsolete Lagoons: The existing sewage lagoons needed to be closed in accordance with DEQ regulations.
    • Regulatory Compliance: Ensuring compliance with DEQ requirements while addressing the infrastructure issues.

Solution

To address these challenges, HECO Engineers developed a comprehensive Wastewater Facilities Plan, which received DEQ approval in July 2014. The plan provided multiple solutions to improve the system, ensuring regulatory compliance and long-term efficiency. Additionally, HECO Engineers prepared a Lagoon Closure Plan to decommission the old lagoons safely.

• • • Seepage Mitigation: Identified and designed measures to rectify seepage issues in the treatment lagoons.
    • I&I Reduction: Implemented strategies to minimize inflow and infiltration in the collection system.
    • Addendum Preparation: Prepared an Addendum to the 2014 Plan, approved by DEQ in May 2016, detailing specific project elements to meet regulatory requirements within funding limitations.
    • Lagoon Closure Plan: Developed a Lagoon Closure Plan, approved by DEQ, to decommission the obsolete lagoons, ensuring environmentally safe closure procedures.
    • Funding Assistance: Assisted the City of Seneca in securing necessary funding for the project.

Results

The collaboration between HECO Engineers and the City of Seneca led to substantial improvements in the wastewater system. The project not only achieved regulatory compliance but also enhanced the overall efficiency and sustainability of the infrastructure. The successful closure of the old lagoons further ensured environmental safety and readiness for potential future site use.

• • • Compliance Achieved: The wastewater system now meets DEQ regulations.
    • Enhanced Efficiency: Reduced seepage and I&I, resulting in more efficient treatment and storage.
    • Sustainable Solutions: Long-term sustainability of the municipal wastewater system ensured through practical and economically feasible solutions.
    • Successful Lagoon Closure: The old lagoons were safely decommissioned, adhering to environmental regulations and preparing the site for potential future use.
    • Community and Environmental Benefits: Prioritized the well-being of the community and environmental protection.

Commitment to Sustainable Wastewater Solutions

HECO Engineers’ work on the Seneca Wastewater Facilities Plan and subsequent improvements, including the lagoon closure, highlights their dedication to providing effective and sustainable engineering solutions. By addressing critical infrastructure challenges and ensuring long-term compliance and efficiency, HECO Engineers exemplifies their commitment to client satisfaction and environmental stewardship.

Contact Heco Engineers to learn more about how we can help you with your wastewater engineering project.