Engineers report large unaccounted water and excess sewer inflows; AIA study to guide fixes and rate adjustments

Willis Engineers presented the results so far of an asset inventory and assessment (AIA) for Burke County's water and sewer systems, a project funded by a $500,000 grant from the North Carolina General Assembly.

Why it matters: The AIA will guide capital, operational and rate decisions for county water and sewer utilities. The study aims to identify physical defects in pipes and manholes, improve the county's GIS mapping of assets, and produce a long‑term financial plan that avoids subsidizing utility operations from county tax revenues.

Major findings and methods: The consulting team said it combined as‑built drawings, field reconnaissance, hydrant testing, 11 temporary flow monitors, smoke testing (about 50,000 linear feet of sewer line), and CCTV inspection planning to establish the inventory and diagnose defects.

Key network stats presented (study team): - Water: roughly 2,300 county customer connections, about 100 miles of distribution pipe, 386 hydrants, five storage tanks and eight booster pump stations; Burke South is the largest system (about 437,000 gallons per day average). - Sewer: about 185 customer connections, roughly 19 miles of collection line, four pump stations, 429 manholes and 12 miles of force main on the sewer side.

Unaccounted for water and sewer losses: Willis Engineers reported that the Burke South water system shows particularly high unaccounted-for water—roughly 48% in the data set supplied to consultants—while the countywide water systems combined show about 40–42% unaccounted for. Chuck Willis cautioned that the number likely represents a mix of metering, billing and physical loss issues that require further investigation.

On the sewer side, flow monitoring showed strong evidence of storm-related inflow. Willis showed a sample monitoring graph where a small rainfall event caused flows to spike from roughly 30–40 gallons per minute to more than 1,100 gallons per minute at a monitored location, a pattern consistent with inflow and defects in manholes and service connections.

Field defects and next steps: The firm reported about 20 broken cleanout caps and 52 manholes that emitted smoke during smoke testing, indicating likely points of inflow. The consultants said many manhole defects and a handful of mainline defects could be repaired to reduce I&I; manhole repairs and targeted CCTV would be the next field work.

Billing and accounting issues: The county manager and consultants emphasized there are also billing-accounting mismatches and intergovernmental complexities. Burke County buys water in bulk from several municipalities and sells to county customers; multiple purchase and resale arrangements complicate meter accounting and can make it appear the county is losing water when the discrepancy is in the billing data or in how master meters and retail meters are reconciled. Similar difficulties appear on sewer when municipalities feed wastewater into county collection systems and the county then transfers it for treatment.

Financial outlook: Efley told commissioners 2024 was the first recent year with a positive cash flow in the utility fund, largely because of improved metering at treatment facilities and preliminary operational improvements. Willis Engineers said the final AIA will include life‑cycle cost calculations, a capital improvement plan for the utilities, and a long‑term rate model to achieve self‑sustaining enterprise funds while smoothing rate changes for customers.

Selected quotes: - "The best thing we can do is just stop it all day until we figure it out. Obviously, that's not realistic," Chuck Willis said describing how persistent losses must be investigated in sequence. - "In 2024 was the first year of positive cash flow in a long time," County Manager Bridal Efley told the board while introducing the study results.

Next steps: The consultant team said they will complete manhole inspections and CCTV scopes over the next months, run life-cycle and rate modeling, and present a final asset management plan that will include recommendations for prioritized repairs, metering changes and potential interlocal agreement updates with municipal partners.

Provenance: Presentation and Q&A during the Burke County Board of Commissioners work session asset inventory and assessment segment.