Composting Technology RFP Guide – What to Specify and How to Evaluate

A good composting technology RFP states the results the facility must achieve, asks every vendor for the same evidence, and publishes how proposals will be scored. Specify outcomes (tons processed, pathogen reduction records, emission limits, product quality) and leave the method open, so that windrow, aerated static pile, covered, enclosed and in-vessel suppliers can all respond. Then judge them on proof, not on brochures.

Key takeaways

  • Write performance specifications first. Use prescriptive detail only for things the site or the permit fixes.
  • Ask for evidence in a set form: full test reports with test conditions, temperature records from an operating facility, and references you can visit.
  • Publish the evaluation factors and their relative importance in the RFP. For federally funded procurements this is a requirement.
  • A vendor that drafts your specification may be barred from bidding if federal funds are involved. Decide who helps you write the RFP before anyone does.
  • Compare cost over the life of the facility, including labor, energy, water, consumables and replacement parts, not purchase price alone.
  • Visit an operating reference site with similar feedstock and climate before you score.

Decide what you are buying

Composting procurements fail most often because the scope was unclear. Settle three questions before drafting.

Technology supply, design-build, or design-build-operate? A technology supply contract buys equipment, design input, commissioning and training. A design-build contract adds the civil works. A design-build-operate contract adds years of operation. Each needs different qualifications and a different risk split.

RFP or sealed bid? Under the federal Uniform Guidance, 2 CFR 200.320 describes sealed bids as a method where a firm fixed-price contract goes to the lowest responsive, responsible bidder, and it calls for “a complete, adequate, and realistic specification” for sealed bidding to be feasible. The same section describes proposals as the method used “when conditions are not appropriate for using sealed bids”, with award to the offeror whose proposal is most advantageous considering price and other factors. Technology selection, where methods differ and quality matters, usually suits the proposal method. The civil construction that follows often suits sealed bids. These federal rules apply only when a federal award funds the purchase. Your state and local procurement law applies in every case, so confirm the method with your purchasing office.

What is fixed? List what the vendor cannot change: the site boundary, the permitted tonnage, the feedstocks, the hours, existing equipment you will keep. Everything else should be open.

If you have not settled the method family yet, the methods comparison and the ranked list of composting technology companies are a quick way to see the range of suppliers your RFP should be able to accommodate.

Performance specifications vs prescriptive specifications

A prescriptive specification says how: “provide a concrete tunnel with a biofilter of a given size”. A performance specification says what: “process the stated tonnage and feedstock mix, and meet the stated limits, on the stated site”.

The federal rule points the same way. 2 CFR 200.319 requires a clear and accurate description of the technical requirements, says “detailed product specifications should be avoided if at all possible”, and lists “specifying only a brand name product instead of allowing an equal product to be offered” among the practices that may restrict competition. Where it is impractical or uneconomical to describe the technical requirements, the section allows a “brand name or equivalent” description, with the specific features of the named brand clearly stated.

Requirement Prescriptive wording (avoid) Performance wording (prefer)
Throughput A fixed number of bays of fixed size Process the stated tons per year of the stated mix within the stated site area
Pathogens A named process or product Meet the time and temperature standard in the permit, with logged records for every batch
Air emissions A named control device Meet the VOC and ammonia limits of the applicable air district rule, shown by source test
Odor A named cover or filter Meet the odor conditions of the permit at the property line; submit an odor management plan
Water A roof Keep stormwater separate from process water; state the volume of leachate to be managed
Product A named screen Meet the stated maturity, stability and contamination limits, shown by lab analysis
Controls A named software package Log temperature per batch at stated intervals; export records in a form the regulator accepts

Some prescriptive items are legitimate: the electrical service you have, the loader you own, a setback the permit fixes. State those as site constraints.

What to require from every vendor

Ask for the same package from each proposer, in the same order, so the evaluation panel can compare line by line.

Pathogen reduction records

Ask for actual batch temperature logs from an operating facility using the proposed system, not a statement of compliance. For biosolids, the federal standard is in 40 CFR Part 503, Appendix B: for within-vessel or static aerated pile composting, 55 degrees Celsius or higher for three days; for windrow composting, 55 degrees or higher for 15 days or longer with a minimum of five turnings. EPA does not certify composting systems or vendors. Compliance is shown batch by batch, by the operator’s records. Under 40 CFR 503.17, the preparer must keep the required pathogen and vector attraction reduction information for five years, so ask how the system stores and exports data over that period. For other feedstocks, cite your state’s composting rule.

Emissions test data and test conditions

A control percentage means little without its conditions. For every emissions claim, require:

  1. the full test report, not a summary
  2. who ran the test and which laboratory analyzed the samples
  3. the test method and whether an agency approved the protocol
  4. the feedstock mix, pile age and season during the test
  5. the baseline the result is compared against
  6. whether the result covers the active phase, curing, or both

As an example of what a regulator asks for, South Coast AQMD Rule 1133.3, as amended September 5, 2025, requires operators that use an emission control system to show compliance by source testing within one year of startup and every three years after, under a source test protocol approved by the agency. Check the current text of the rule that applies to your site, and ask each vendor whether its data was produced under a comparable approved protocol. The list of ways to reduce VOC emissions explains the control options you may see proposed.

Odor evidence

Ask for the odor management plan from a reference facility, its complaint history as recorded by the operator or the local agency, and any olfactometry reports with their methods. Do not score on a headline figure alone.

References

Require at least three operating facilities, with contact names, that match your case on as many of these as possible: feedstock, tonnage, climate, and regulatory setting. Ask for years in operation and for one reference where something went wrong and how it was resolved. A set of independent case studies can help you check what vendors tell you.

Training and commissioning

Require a written plan: who trains, how many days on site, what topics, and what the acceptance tests at commissioning are. Ask what remote support is available afterward and during which hours.

Warranty, spare parts and consumables

Ask each vendor to state, in a table:

  • warranty terms by component (blowers, controls, sensors, covers or media, structures)
  • what voids the warranty
  • expected service life of wear items under your conditions
  • a recommended spare parts list and typical lead times
  • software licensing, update and data ownership terms

Life-cycle inputs

Require the quantities, not only the prices: operator hours by task, electricity use per ton, fuel, water, consumables, and scheduled replacements over the evaluation period. With quantities in hand you can apply your own local rates to every proposal. SG’s article on infrastructure decisions and long-term budgets is one supplier’s view of why this matters.

Evaluation criteria and weights

Publish the factors and their relative importance in the RFP. Where a federal award is involved, 2 CFR 200.320 requires that “all evaluation factors and their relative importance must be identified”, and that the agency have written procedures for technical evaluations.

The table is an illustration of how a panel might divide 100 points. It is not a standard. Adjust it to your priorities and your procurement rules.

Factor Example points What the panel scores
Technical approach and fit to site 20 Mass balance, layout, footprint, water plan
Regulatory performance evidence 20 Quality of pathogen, emissions and nuisance evidence, and its test conditions
Reference facilities 15 Similarity to your case, reference calls, site visit findings
Life-cycle cost 25 Capital plus operating quantities at your rates over the stated period
Operability and staffing 10 Tasks, skills needed, safety, controls and records
Training, support and warranty 10 Plan detail, response commitments, parts

Two practices keep scoring defensible. Score technical factors before opening price. Write a short reason for every score.

Questions to ask every vendor

Put the same questions to all proposers, in writing.

  1. What is the smallest and largest operating facility using this system, and which is closest to ours?
  2. What happens to throughput if our feedstock is wetter or denser than assumed?
  3. What does the operator do each day, each week and each batch?
  4. Which components fail most often, and what does replacement involve?
  5. How is process air and process water handled, and what leaves the site?
  6. What does the system need from us: power, water, pad, equipment, bulking agent?
  7. What happens during a power outage, a hard freeze or a major storm?
  8. How does the facility expand, and what has to be rebuilt to do it?
  9. Who owns the operating data, and can we export all of it?
  10. What have regulators asked of your other customers after startup?

Site visit checklist

Visit on a normal operating day, and talk to the operators without the vendor present if you can.

  • Stand at the property line downwind. Note what you smell and the weather.
  • Watch receiving and mixing: how long does fresh material sit before it is in process?
  • Look at the pad and drains during or after rain if possible.
  • Ask to see batch temperature records for the last month.
  • Ask what broke last year and how long the repair took.
  • Count the people and machines actually working.
  • Look at the finished product pile and ask for recent lab results; the key metrics for compost quality list shows what to look for.
  • Ask the operator what they would change if they built again.

Mistakes that restrict competition or invite protest

  • Letting a bidder write the specification. Under 2 CFR 200.319(b), contractors that develop or draft specifications, requirements, statements of work or invitations for bids must be excluded from competing on those procurements when a federal award is involved. Many vendors offer help with RFPs; Sustainable Generation, for example, lists RFP assistance among its project initiation services. Such help is common. The federal rule comes into play only when the same vendor then wants to compete for a federally funded purchase. Use vendor input through an open request for information that all suppliers can answer, or hire an independent consultant, and check your own rules.
  • Experience requirements only one firm can meet. The same section lists “requiring unnecessary experience and excessive bonding” among practices that may restrict competition.
  • Scoring on factors you did not publish.
  • Accepting claims without reports. If a number has no test report behind it, score it as unsupported.
  • Skipping the pilot when the feedstock is unusual. A short on-site trial can be written into the procurement as a stage. See the pilots and demos page for how one supplier structures a trial.

FAQ

Should a composting RFP name a technology?

Usually not. Naming one method removes suppliers who could meet your goals another way, and for federally funded purchases 2 CFR 200.319 discourages detailed product specifications and brand-name-only requirements. State the results you need and the site constraints. If a permit already fixes the method, say so and cite the permit condition.

How many reference facilities should we require?

Three operating facilities is a workable minimum, with at least one that matches your feedstock and one in a similar climate. Quality matters more than count: a single site with your feedstock, your tonnage and several years of records tells you more than ten dissimilar ones. Call every reference and visit at least one.

How do we compare cost across different technologies?

Ask every vendor for quantities over the same period: capital items, operator hours, electricity, fuel, water, consumables and scheduled replacements. Then apply your own wage, power and water rates to each proposal. This puts a low-capital, high-labor method and a high-capital, low-labor method on the same basis.

Do federal procurement rules apply to our project?

Only if a federal award pays for part of it, in which case the procurement standards in 2 CFR Part 200, including sections 200.319 and 200.320, apply to that purchase. Your state and local procurement law applies either way. Ask your grants manager and purchasing office before you issue the RFP.

Next step

If Sustainable Generation is one of the suppliers you plan to invite, send the draft evidence list above and ask which items it can supply for your feedstock and district. Start at the contact page, and review the project profiles for candidate reference sites.

Related guides

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