A city or county buys a composting system well when it makes six decisions in order: how much material and of what kind, on which site, owned and operated by whom, procured how, acceptable to which neighbors, and approved on what evidence. The technology choice comes fourth or fifth in that sequence, not first. Covered aerated static pile (ASP) composting fits many municipal programs that add food scraps, but not all of them, and this guide says where it does not.

Key takeaways

• Forecast tonnage as a curve, not a single number. Food scrap collection ramps up over several years, and the system should be able to grow with it on the same site.
• The site decides more than the brochure does. Buffers, power, water, stormwater and what lies under the pad narrow the technology options before any vendor is called.
• Decide who operates before you write the procurement. Own and operate, design-build-operate and merchant capacity put risk and control in different places.
• A pilot with your own feedstock produces the evidence that a board, a permit writer and a grant reviewer all ask for.
• Leaf and brush programs with large buffers often do not need a covered system, and programs that want energy from food waste should look at anaerobic digestion first.

Step 1: Forecast tonnage and feedstock

Start with what the collection program will deliver, by material and by season. Yard trimmings peak in spring and fall. Food scraps arrive every week, wet and dense, and they change the site: more leachate, more vector pressure, and more attention from air and solid waste regulators.

Policy is the reason most municipal programs are adding food scraps. The U.S. Environmental Protection Agency estimates that 58 percent of the fugitive methane from municipal solid waste landfills comes from landfilled food waste (EPA, Quantifying Methane Emissions from Landfilled Food Waste). In California, SB 1383 set a statewide goal of 75% less organic waste sent to landfills by 2025, and it requires every jurisdiction to provide organic waste collection to all residents and businesses (CalRecycle). The list of SB 1383 requirements covers the detail.

Build the forecast in three lines:

1. Committed tonnage: material your own crews or franchise haulers already collect.
2. Program growth: participation you expect as carts roll out, by year.
3. Third-party tonnage: commercial haulers who may tip at your site if you let them.

Record the food scrap share of the mix separately. It drives the amount of bulking material you need, the emission controls you may be required to install, and how quickly a pile turns anaerobic if aeration is poor. Also write down the contamination you expect from curbside carts. The City of San Diego’s Miramar Greenery is a useful reference: SG’s profile says the city was composting green waste in turned windrows and looked for a different method when food waste and contamination from automated curbside collection entered the stream (profile).

Step 2: Test the site before the technology

Most municipalities do not choose a site freely. They have a landfill, a transfer station, a public works yard or an existing leaf compost pad. Check each candidate against the same questions:

• Distance to neighbors and the direction of prevailing wind.
• What is under the pad. A closed landfill cell settles. SG’s profile of the DSNY Staten Island Compost Facility says the first project phase dealt with the geotechnical challenges of operating on a closed landfill and took several construction stages (profile).
• Power for blowers and controls, and the cost in time of extending it.
• Water, for moisture addition in dry climates and for fire protection.
• Stormwater and leachate. Clean runoff and process water should leave the pad by separate routes. SG’s article on keeping stormwater and leachate separate explains why.
• Room to expand to the last year of your forecast, including curing, screening and product storage.

The facility design guide shows how to turn tonnage into pad area. If the site cannot hold the final-year tonnage with the method you have in mind, change the method or the site now, not after the bond is sold.

Step 3: Decide who owns and who operates

This is the decision that shapes the procurement, and it is the one most often left until too late.

Model	What the municipality does	What it gains	What it gives up or risks
Own and operate	Buys the system, staffs it, sells or uses the compost	Full control of feedstock rules, product and schedule	Carries staffing, training and performance risk
Public owner, contract operator	Owns the site and system, hires a firm to run it	Keeps the asset and the permit, buys operating skill	Needs a strong contract and someone to manage it
Design-build-operate	One contract for design, construction and operation	Single point of accountability, faster delivery	Less say in design detail, long contract term
Merchant capacity	Sends material to a private facility under contract	No capital, no site, no staff	Depends on a facility it does not control, and on haul distance

SG’s Staten Island profile shows the middle model: it lists the New York City Department of Sanitation as owner and Denali Water Solutions as operator under contract. SG’s profile of the Prince George’s County facility in Upper Marlboro lists Maryland Environmental Service under ownership and does not describe the operating arrangement, so ask the county or SG if that model interests you (profile).

If you plan to operate with your own staff, read the staffing and operator training guide before you set the budget. SG’s pages describe design support, installation guidance, on-site commissioning, operator training and ongoing technical support (operator training support). They do not describe SG as a contract operator, so a city that wants one firm to run the facility should plan to hire that operator separately and ask SG about it directly.

Step 4: Match the method to your tonnage, rules and neighbors

Only now compare technologies. The neutral comparison is in composting methods compared; the table below is the short municipal version.

Your situation	Method that usually fits	Why	Watch for
Leaves and brush only, large buffer, no air district rule	Turned windrow	Lowest infrastructure, familiar equipment	Long residence time, large pad, exposed to rain
Yard trimmings plus a growing share of food scraps, neighbors within sight	Covered ASP	Aeration without turning, emissions and rain managed at the pile	Needs power, a trained operator and cover handling
Food scraps, tight site, emission capture required by permit	Covered ASP, or negative ASP with a biofilter	Both treat process air	Biofilter media, condensate and fan energy for the negative option
Dense urban site, no outdoor operation allowed	In-vessel or enclosed building	Full enclosure	Highest infrastructure and maintenance
Food waste with a goal of energy recovery	Anaerobic digestion, with composting of the digestate	Produces biogas	Digestate still needs an outlet

Sustainable Generation (SG) supplies the covered ASP option: SG Advanced Composting™ Technology with the GORE® Cover, positive aeration controlled by oxygen and temperature feedback through the SG COMPOST CONTROL™ System, and no building or biofilter. SG’s How It Works page describes a 4 to 8 week treatment time versus 8 to 12 months for open windrow. SG rates the SG HEAP® System at 1,000 to 100,000+ tons per year and the SG BUNKER® System at 5,000 to 500,000 tons per year, and it describes the SG MOBILE® System as installed in days to weeks, depending on the site. The municipal solid waste page is SG’s own summary for this buyer.

For neighbors, the question is where emissions are managed. Covered ASP with a GORE Cover is designed to contain odors at the pile. Receiving, mixing and screening still happen in the open with any outdoor method, so the odor plan has to cover them too. See the odor control list for the options.

Step 5: Pilot, then procure

A municipal board rarely approves a technology on a vendor’s word, and it should not. A pilot run on the candidate site with local feedstock answers the questions that matter: does the mix reach pathogen reduction temperatures, what does the fence line smell like, how much labor does a batch take, and is the compost good enough to give away or sell.

Prince George’s County is the clearest example in SG’s material. According to SG’s profile, the county piloted an SG MOBILE System in 2013 to test green waste and food waste, compared the 8-week process against its existing 8-month windrow process, added units over the next three years to reach 12,000 tons per year, and installed 12 SG BUNKER Systems in 2018 for a facility SG lists at 57,000 tons per year. The DSNY profile describes a different path: a consultant-led technology evaluation in 2014 to 2015 against three stated requirements (air quality compliance focused on odor and VOC emissions, separation of leachate from stormwater, and compost quality), followed by a 16-bunker installation.

Procurement steps that work for either path:

1. Write performance requirements, not a brand name: tonnage, feedstock mix, pathogen reduction records, emission test data with test conditions, stormwater separation, training and support.
2. Ask every proposer for municipal references with food waste in the mix, and call the operators.
3. Visit a reference site on a normal working day.
4. Score lifecycle cost drivers, not purchase price alone. The lifecycle cost guide lists them.
5. Decide whether to lease pilot equipment or buy it. SG’s leasing program names bridging gaps between grant phases as a municipal use.

The RFP guide has the full specification checklist.

For funding, check EPA’s Solid Waste Infrastructure for Recycling program. EPA lists political subdivisions as one of its three funding tracks and says the program was funded for fiscal years 2022 to 2026 (EPA SWIFR). As of October 2026, check that page for any open round before you count on it.

Step 6: Take it to the board

Board members ask about four things: risk, neighbors, operating budget and what happens if tonnage does not arrive. Bring them:

• [ ] The tonnage forecast with low, expected and high cases
• [ ] The site review, including buffers and expansion area
• [ ] The operating model and who carries which risk
• [ ] Pilot data, or a plan and schedule to get it
• [ ] Reference calls, written up
• [ ] The permit path and who prepares each application
• [ ] The compost outlet: city departments, residents, sales. In California, SB 1383 also requires cities and counties to procure recovered organic waste products such as compost and mulch each year (CalRecycle procurement)
• [ ] A phasing plan that lets the board approve one stage at a time

Meet neighbors before the hearing, not at it. Show them the pilot, explain the complaint process, and name the person who answers the phone.

Where covered ASP or SG is not the right fit

• Leaf and brush only, far from anyone. A turned windrow pad is simpler and needs no power at the pile.
• Unsorted mixed waste. Composting works on source-separated organics. A mixed waste stream needs sorting equipment that no composting system supplies.
• No outdoor site at all. Covered ASP is an outdoor method. A fully enclosed plant is a different project.
• Very small programs. If the forecast is a few hundred tons a year with no plan to grow, a contract with a merchant composter may serve residents better than owning a facility.

FAQ

How much food waste can a municipal covered ASP system take?

It depends on the mix and the bulking material available, so test it. SG’s profile of Prince George’s County says the pilot there validated composting food waste at mix levels up to 50 percent, with compost inside the county’s quality specifications. Your own limit will depend on moisture, the supply of wood chips or yard trimmings, and any limits in your air or solid waste permit.

Should a city own the composting system or contract for capacity?

Own it when you have a site, a long-term supply of material and a reason to control the product, such as city use of compost. Contract for merchant capacity when tonnage is small or uncertain, or when no workable site exists. A middle path, public ownership with a contract operator, keeps the asset and the permit public while buying operating skill.

Do we need a pilot if other cities already run the same system?

Other cities prove the technology works. A pilot proves it works with your feedstock, on your site, with your staff and your neighbors. It also produces local data for permit applications and grant proposals. SG’s pilots and demos page describes pilots as a way to generate performance data for permits, grants or board approval using actual batches of the owner’s feedstock.

What should we ask vendor references?

Ask the operator, not only the director. How many staff run the site on a normal day, what broke in the first year, how the vendor responded, how often neighbors call, whether compost quality has been steady, and what they would change in the design. Ask for pathogen reduction records and any emission test reports with their test conditions.

Next step

If you have a tonnage forecast and a candidate site, send both to SG and ask for a preliminary layout and a pilot plan. Use the contact page, or read about pilots and demos first if the board will want local data.

Related guides

• Composting Technology RFP Guide
• How to Run a Composting Pilot
• Composting at Landfills
• Organics Diversion and Food Waste Laws by State
• How to Fund a Compost Facility

← All commercial composting guides

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