Environmental & Landfill Civil
We are the civil subcontractor environmental firms bring in for the concrete, underground and site work around their systems: flare station and blower foundations, landfill gas header and duct bank trenching, storm drain, swales and paving, built by our own crews on active sites to the engineer's plans. Prevailing-wage projects accepted as a subcontractor.
Who it's for
- Environmental engineering and field services firms that run landfill gas, leachate and remediation systems and need one civil sub for the work around them
- Prime contractors bidding public landfill and solid waste projects who need a Class A civil subcontractor on their bid
- Landfill owners and operators with flare, drainage, paving or utility work on an active or closed site
- Developers of closed-landfill and brownfield sites who need underground and site work built around gas protection systems
- Renewable energy and RNG developers building equipment pads, duct banks and site utilities at landfills
How the work goes
- Send us the plans and bid schedule. The civil, structural and electrical sheets, the geotechnical report and your bid schedule. We price line by line to match it.
- Walk the site. We review access, the work area, existing gas headers and utilities, and the site's health and safety plan before we price.
- Locate and pothole. We locate existing lines and expose crossings with our own hydrovac before excavation starts.
- Prepare the subgrade. Over-excavation, compaction and grading to the geotechnical engineer's requirements, with testing by the project's inspector.
- Build the foundations and underground. Forming, rebar and concrete for equipment foundations and pads, plus trenching, conduit, pull boxes and vaults, and storm drain, to the engineer's plans.
- Inspect before cover. Nothing is backfilled or poured until the inspector or the engineer signs off.
- Restore and hand off. Backfill, paving, swales and fencing put back, and the pads turned over to the environmental firm to set equipment.
What drives the cost
- Foundation size, depth and rebar, and whether piles or over-excavation are required
- Distance and depth of trenching, and how many existing headers and utilities have to be crossed
- Site access, haul routes and where export can go on site
- Standby time while equipment, piping or other trades are set
- The site's safety requirements and working hours
- Prevailing wage and certified payroll on public projects
- Testing, inspection and agency fees, which the owner pays directly
What we do differently
One Class A civil sub for the concrete, underground and site work around the environmental firm's system.
The civil package around your system
Environmental firms bring the process: the gas collection system, the flare, the blowers and the controls. Around that sits the civil work, from the pads and foundations to the trenches, the drainage and the road back in. We carry that package with our own crews and equipment, so you deal with one civil subcontractor instead of a concrete crew, an excavation crew, an electrical trencher and a paving company.
What we build
- Flare station and equipment foundations. Flare, blower skid, VFD and control building foundations and pads, including pile-supported pads where the plans call for them.
- Subgrade preparation and grading. Over-excavation, recompaction, pad grading and rough grading to the geotechnical engineer's requirements.
- Landfill gas header and condensate trenching. Excavation, bedding, backfill and surface restoration for header, lateral and condensate lines, built around the environmental firm's piping crew.
- Electrical and Edison underground. Duct banks, conduit, pull boxes, vaults and equipment pads, from our years of Edison and LADWP underground work.
- Storm drain and erosion control. Storm drain removal and replacement, concrete swales, splash walls, downdrains and drainage structures.
- Paving and access roads. Asphalt paving, trench patching and access-road repair, including pavement put back after the underground is done.
- Hydrovac potholing. Non-destructive digging to expose live gas, electrical and water lines before the trench is cut. See hydro-excavation.
Where we have built
Since 2022 we have worked as a civil subcontractor at active landfills in Castaic, Palmdale, Santa Paula, Corona, Sylmar and Santa Maria. The work has included three equipment foundations, a gas header and storm drain replacement for a new flare station, subgrade preparation and a concrete flare pad, flare replacement foundations, a concrete pad with a 32-foot stem wall, concrete swales and splash walls, and paving improvements and asphalt trench repair. See more on our projects page.
Working on an active landfill
A landfill is an operating site. Trucks keep moving, landfill gas can be present, and the gas system has to stay running while we work around it. Our crews work to the site's health and safety plan, including landfill gas awareness, hot-work controls and the site's traffic rules. Every excavation is run by an OSHA-trained competent person under our Cal/OSHA annual trench and excavation permit, and nothing is covered until it is inspected.
How we work with environmental firms and primes
We work as a subcontractor to the environmental firm or the prime contractor. On landfill and environmental projects we take prevailing-wage work as a subcontractor, including public solid waste projects. Proposals follow your bid schedule, line by line, so you can compare and award without guessing what is included. Design stays with the engineer of record: we build to the approved plans, and where a field change is needed, the engineer approves it first.
Licensed for the work
J.F. Prieto Engineering Construction, Inc., Lic. #525452, Class A General Engineering, Class B General Building and HAZ. Our HAZ certification covers hazardous substance removal work. We hold a Cal/OSHA annual trench and excavation permit and keep a written injury and illness prevention program and a 70-section safety manual. Based at 5180 Alhambra Ave., Los Angeles, with crews traveling to projects across Southern California.
Common questions
Do you work at active landfills?
Yes. We have built flare station foundations, landfill gas header trenches, storm drain, swales and paving at active landfills in Southern California, working as the civil subcontractor to the environmental firm that runs the gas system. Our crews work to the site's health and safety plan.
Do you take prevailing-wage work on environmental projects?
Yes, as a subcontractor. On landfill and environmental projects we work under the environmental firm or the prime contractor, including public projects that pay prevailing wage. We do not bid public works as the prime contractor.
Do you design the flare pad or gas system?
No. We build to the engineer's plans and specifications. Design of the gas system, the flare and its foundations stays with the engineer of record. Where a field change is needed, the engineer approves it before we build it.
What civil work do you self-perform on a landfill project?
Concrete foundations and pads, excavation and grading, underground utility and electrical duct bank trenching, storm drain, swales and splash walls, asphalt paving and patching, and hydrovac potholing. Our own crews and equipment do the work.
Where we do this work
From the field
Ready to talk about your project?
Send us the details and we will follow up with next steps, or call us directly.