City of Roseville — Closed Landfill Compliance Monitoring
Deputy project manager for Title 27 compliance at the City of Roseville’s closed, unlined landfill: coordinating the semiannual groundwater sampling, running the landfill gas monitoring, and helping write the reports the Regional Water Board relies on.
- Client / program
- City of Roseville
- My role
- Deputy project manager (DPM)
- Dates
- Jan 2025 — Present
- Location
- Roseville, CA
- Status
- Active
Ocean 40° N 35° N 120° W
Problem
An unlined landfill closed in 1995 still has to show the Regional Water Board, twice a year, that its groundwater, the creek running through it and the gas at its boundary are under control.
Approach
Run each semiannual cycle end to end: coordinate the groundwater sampling, monitor the landfill gas, then turn the results into a regulator-ready report, with a Python diff that keeps last cycle’s text from going stale.
Outcome
Semiannual reports that are internally consistent and defensible, submitted on schedule under the site’s Title 27 monitoring program.
Setting
The Roseville Landfill took the city’s waste from 1967 to 1979, on 115 acres about a mile north-east of downtown. It was closed in 1995 under a clay cover, and the city grew up around it: Roseville Parkway now runs across part of the old waste, and the Antelope Creek Trail crosses the site where the creek itself still flows through, between the waste units, on its way to Dry Creek.
Like most landfills of its age, it was never lined. Three units remain, one of them two older units now regulated as one, sitting on native ground with no leachate collection beneath them. Chlorinated solvents turned up in the groundwater in the late 1980s, and landfill gas once reached high levels in the perimeter probes. Closure, together with a set of passive, wind-turbine gas vents, was the corrective action, and the monitoring is how anyone knows whether it is still working.
The monitoring
The site is regulated by the Central Valley Regional Water Quality Control Board under Waste Discharge Requirements and a Monitoring and Reporting Program (Order R5-2019-0056), written under CCR Title 27. The network is:
- 14 groundwater monitoring wells on site (two more off site are sampled voluntarily), measured quarterly for water levels;
- three surface-water stations on Antelope Creek, upstream, between the waste units and downstream;
- nine perimeter landfill-gas monitoring locations, most with probes at two depths, checked for methane, carbon dioxide and organic vapors.
Twice a year all of it comes together in a semiannual compliance report, filed with the Regional Board: every result compared against its limits, the background wells against the compliance wells, each constituent read against years of history, and a judgment on whether the corrective action is still doing its job.
My role
I am the deputy project manager (DPM) for the City’s compliance program at the landfill, keeping it in line with Title 27 and the site’s Monitoring and Reporting Program, for groundwater and for landfill gas. Each six-month cycle:
- Groundwater. I coordinate the semiannual groundwater sampling event: scheduling, the sampling team, laboratory analyses and deliverables.
- Landfill gas. I conduct the semiannual landfill gas monitoring at the perimeter probes, with a Landtec GEM 5000 gas analyzer and a MiniRAE 3000 PID.
- Reports. I help draft the semiannual and annual monitoring reports: QA/QC of the laboratory data, trends against the multi-year record, background against compliance wells, and the corrective-action picture, prepared for review, certification by a professional engineer, and submittal.
- The project. As DPM, I help keep the schedule, scope and deliverables on track for the City.
Keeping a cyclic report true
A report written every six months for decades has one characteristic failure: a sentence carried over from the last cycle that is no longer true. The table was updated, the paragraph that describes it was not, and nothing about the document looks wrong.
I hold the report to one rule, diff every number against its source, and built a small Python tool to make that rule cheap to follow: it compares the new report to the last one paragraph by paragraph and color-codes what carried over, what changed and what is new, so review goes where stale text hides. I wrote about the method in “Diff every number”, and the tool is in Tools.
Skills demonstrated
Deputy project management of a Title 27 compliance program; coordinating groundwater sampling; landfill gas monitoring and field instrumentation; laboratory data QA/QC and trend review; corrective-action evaluation at an unlined closed landfill; technical writing for regulators; and Python tooling for report QC.