Geomembrane Wastewater Pond Liner Case Study
WHO WE ARE
Project Overview
- Name: New Plymouth Pond 4 Liner Installation
- Type: Wastewater Infrastructure Upgrade
- Location: New Plymouth, Idaho
- Specialty: Environmental Compliance, Wastewater Management
Provided Services
HECO Engineers delivered comprehensive consulting and engineering services, including:
- Preliminary project design and specifications
- Subgrade preparation, grading, and compaction verification
- Installation oversight of the geomembrane liner system
- Upgrades to existing piping and control boxes
- Construction observation and compliance verification
- Hydrostatic testing to confirm liner performance
Problem
The City of New Plymouth faced challenges with its aging wastewater Pond 4 lagoon:
- The lagoon system required a seepage prevention solution to protect local groundwater and meet Idaho Department of Environmental Quality (DEQ) standards.
- The existing infrastructure, including piping systems and control boxes, needed upgrades to improve operational efficiency and reliability.
- The project needed to align with American Rescue Plan Act (ARPA) funding requirements while staying on schedule and budget.
These challenges required a thoughtful, sustainable, and compliant solution to ensure long-term performance for the City’s wastewater infrastructer.
Solution
HECO Engineers partnered with the City of New Plymouth to deliver a modern, compliant wastewater management solution. The project focused on three key areas:
Geomembrane Liner Installation
- Seepage Control: A high-performance geomembrane liner system was installed to minimize seepage to a regulated limit of 1/8 inch per day, verified through hydrostatic testing.
- Subgrade Preparation: The existing pond bottom was graded, compacted, and tested to meet the liner manufacturer’s requirements for performance and longevity.
- Gas Venting System: Flap vents and an anchor trench were installed to allow for proper venting and secure liner placement.
Piping and Control Box Upgrades
- Piping Enhancements: Modifications to the existing piping system improved water flow management and operational efficiency.
- Control System Improvements: Upgraded control boxes provided more precise monitoring and functionality of the wastewater system.
Construction Observation and Testing
- HECO Engineers provided 1–2 site visits per week to oversee construction, address contractor questions, and verify compliance with all DEQ and ARPA funding standards.
- Hydrostatic testing was conducted to ensure the liner system performed to exact specifications.
Results
The successful completion of the Pond 4 Lining Project delivered critical infrastructure improvements for the City of New Plymouth, including:
- Environmental Protection: The new geomembrane liner system significantly reduces seepage, protecting local groundwater resources and meeting environmental compliance standards.
- Operational Efficiency: Upgrades to the piping systems and control boxes ensure smoother wastewater management and long-term system reliability.
- Funding Utilization: ARPA grant funding was effectively utilized to address the City’s immediate infrastructure needs while providing a sustainable solution for future growth.
- Regulatory Compliance: Rigorous testing and observation ensured the project adhered to DEQ standards, securing the facility’s long-term performance.
About HECO Engineers
At HECO Engineers, we specialize in innovative, practical solutions for water and wastewater infrastructure projects. Our team partners with Idaho communities to deliver sustainable engineering designs that protect natural resources and improve system performance.
Learn More
📞 Contact Us Today: (208) 642-3304
🌐 Visit Us Online: https://hecoengineers.com
