Compost quality testing, answered.

VCAT (Visual Compost Analysis Technology) is compost quality testing software for commercial composting facilities: an operator photographs a pile or windrow with a phone, and VCAT returns a quality assessment in seconds, without sending a sample to a lab. Every report is timestamped, GPS-tagged and tamper-evident, and syncs to a web portal that keeps a batch history for every pile or windrow, from formation to shipment.

VCAT uses computer vision models trained on compost images to read visual quality signals from three photos of a pile. Each report scores five indicators:

• Contamination: the degree of visible physical contamination, such as plastic, glass and metal.
• Particle size distribution: the estimated share of material in each size class, like a sieve analysis produced from photos, with no sampling or shaking required. Use it to check a batch against the screen size or specification your buyers expect before it ships.
• Color-based maturity: how far along the composting process is.
• Feedstock decomposition: recognizable feedstock that hasn't fully broken down.
• Uniformity: whether the batch is consistent enough to ship.

You also get an overall 0–5 score. VCAT sees what a camera can see. It doesn't measure chemistry, pathogens or metals; those still need a lab.

No. VCAT is a decision-support tool, not a lab test, a certification or a compliance instrument. It doesn't replace testing required by the US Composting Council's Seal of Testing Assurance (STA) program, your state permit or any other program. It fills the gap between required lab tests: you can assess any batch, any day, and have a documented record of what you saw. For certified facilities, and those preparing for certification, that means keeping product quality consistent between the lab tests your certification depends on.

No. VCAT runs on the phone your team already carries, with no probes, sensors or cameras to install.

VCAT works well as a screening tool today, flagging batches that need a closer look. We're actively improving the accuracy of every indicator, and the models get better as more facilities' data comes in. Use VCAT scores to decide which batches to check further, cure longer or re-screen, not as a pass/fail verdict on a batch.

Compost maturity is usually tested with a combination of methods: respiration tests that measure CO₂ and ammonia release (such as the Solvita maturity test), self-heating tests, carbon-to-nitrogen ratio, seed germination tests, and the look, smell and temperature of the pile. Lab and kit tests are precise but take time and cost money per sample, so most facilities can't run them on every batch. VCAT adds a visual maturity check that returns results in seconds on any pile or windrow, with every check documented, so you know which batches are ready to move instead of sitting on the pad longer than needed, and which need more curing or a lab test.

Compost testing falls into three groups: accredited lab panels (nutrients, metals, pathogens, stability and maturity), on-site test kits, and visual inspection by operators. Lab panels are required on a set schedule under programs like STA and state permits. Visual inspection happens every day but often leaves no record. VCAT makes that everyday visual inspection objective and documented, so you get consistent scores and a record for every batch between lab tests.

Every VCAT assessment rates the degree of visible physical contamination, such as plastic, glass and metal. That helps a visual check find material a quick look can miss, especially at facilities taking food waste, mixed waste or C&D inputs. The portal's Contamination Flags view lists every report where contamination was flagged, in one place, so you can see which piles, feedstocks or time periods are causing trouble.

VCAT can help you catch contamination problems early, but it doesn't replace the required test. California limits compost to 0.5% physical contaminants larger than 4 mm by dry weight, with film plastic no more than 20% of that. Compliance is checked on a sample for every 5,000 cubic yards produced (at least once a year for smaller facilities), and results must be in before the compost leaves the site (14 CCR § 17868.3.1).

Between those tests, VCAT rates the degree of visible contamination on every batch you assess. Batches trending the wrong way can be re-screened before sampling and before they ship, rather than failing a test and needing reprocessing. Under SB 1383, cities and counties buy compost from permitted facilities, so keeping your product consistently clean protects that market.

VCAT's rating is a visual screen, not the dry-weight measurement the regulation requires. Your required testing continues as your permit specifies.

VCAT flags an immature or contaminated batch early, so you can cure it longer, re-screen it or hold it before the required sampling and before it ships. That means fewer failed tests and fewer nonconforming loads leaving your site. VCAT reports stay your own internal records. They are not compliance evidence to submit to a regulator or certifier, and your required testing continues exactly as your program specifies.

If you send discretionary samples to an outside lab (tests beyond what your program requires), VCAT lets you send the batches that flag a problem instead of testing on a fixed schedule whether or not anything looks wrong. Required tests aren't affected; this is about the optional ones.

Holding a finished batch on the pad “to be safe” ties up space and pushes back sales. With a maturity reading on every check, the batch history shows when a batch has leveled off. You can move it on when it's ready instead of on a fixed schedule, and freeing pad space sooner means more batches a year from the same site.

VCAT is one input to that decision, never the only one. It doesn't measure pathogens. Before any batch is released, it must still meet your required time-and-temperature process for pathogen reduction and any required lab testing, whatever its VCAT scores. Use VCAT alongside your temperature records and other maturity checks to judge when a batch that has met those requirements is ready.

Buyers come back when every load matches what they ordered. By checking maturity, particle size, contamination and uniformity before a batch ships, you catch problem loads while they're still cheap to fix: a few more days of curing costs far less than a rejected load, round-trip freight and an unhappy customer. Over time, your VCAT history also shows you which feedstocks and practices produce your best product.

Yes. VCAT keeps a batch history for every pile or windrow: all the assessments of one batch, from the day it was formed until it ships, in a single timeline. Each batch history shows the formation date, every assessment with its photos, scores, location and time, and charts of each quality indicator and pile temperature over time. You can see whether a windrow is on track, catch one that's falling behind, and export a summary of that batch's full history for your records.

Yes. Many facilities still track batches on clipboards and spreadsheets. VCAT replaces that with a batch record built automatically as your team works: each assessment adds a timestamped, GPS-tagged, photo-documented entry to the batch's history. Corrections are recorded with who made them and why, never silently overwritten. When you need to show how a batch was handled (for your own QA review or to prepare for STA certification), the whole history is already in one place and can be exported as a summary.

Tamper-evident means any change to a report after it was created can be detected. Each VCAT report is sealed at creation with a SHA-256 fingerprint along with its timestamp and GPS coordinates. Anyone can check a report on our free verification page without an account. If a report ever needs a correction, the correction is added to a permanent, attributed record and the original stays intact; nothing is silently overwritten.

A record of every batch shows which feedstocks, recipes and practices produce your best compost, and how long each batch really needs. VCAT builds that record as your team works: each assessment adds a dated, photo-documented entry with the batch's feedstock, method, formation and turning dates, pile temperature and quality scores. Without it, most of that knowledge lives in experience and the occasional lab test.

Yes. By building a batch with the new feedstock or blend and recording its details in each assessment, you can compare it with batches made your usual way, whether they're running at the same time or were made months earlier, because every batch history is kept. You can see how quickly each matures, how its particle size and uniformity develop, and how much contamination the new material brings in. Batches made at the same time give the most direct comparison; between batches from different times of year, weather and season can account for some of the difference.

Yes. VCAT records the last turning date with every assessment, so you can compare batches turned on different schedules by how quickly they heat, mature and even out, with each batch history showing turns alongside temperature and quality scores. Any schedule you test must still meet your required time-and-temperature process for pathogen reduction; VCAT helps you compare schedules that do.

Yes. Every assessment is dated, so you can compare batches formed in different seasons: how long they take to mature, how their temperatures run, and how their quality scores develop. That helps with planning pad space and curing time for the months when batches are slower.

You can compare the batches side by side in the portal. Select up to six batch histories, such as batches made before and after the change, or with and without it, and the portal charts them together, lined up by days since formation so batches from different months start at the same point. You can see which heated faster, matured sooner or finished more evenly, one quality indicator or pile temperature at a time.

An assessment takes about four to five minutes from first photo to a finished report:

1. Tap Start New Report.
2. Take three photos: one overview from about 15 feet away and two close-up texture shots from about 4 feet. The app checks that compost is in each shot.
3. Choose feedstock type, composting method and turning state. GPS is captured automatically.
4. Review the analysis, ready in seconds: the overall 0–5 score and all five indicators.
5. Confirm the report details. If you link the new report to an earlier one from the same pile or windrow, most fields are filled in for you, and the report joins that batch's history.
6. Export: VCAT saves a PDF and data file to your phone or emails them, and syncs the report to your portal.

Yes. The photo analysis runs on the phone itself, so you can assess piles in parts of the yard with no signal. Reports sync to your portal automatically once you're back online.

About four to five minutes per pile. In daily use at a working composting facility, reports typically take around four minutes from first photo to finished report. The analysis is ready in seconds, and when you re-check a pile you've assessed before, most of the report is already filled in from the earlier one. Photos, scores, location and time are captured in one step, so there's no separate paperwork and nothing to transcribe later. The savings grow with the number of batches you assess.

The portal holds every report your team creates. You can follow each batch through its batch history, see all your piles on a satellite map color-coded by any quality indicator, sort and filter your report history, open any report for the full breakdown and photos, review a log of every contamination flag, compare batch histories side by side, and export a summary of your assessment history for your own records.

Yes. The portal exports your assessments for any date range to a spreadsheet (CSV) file with each report's quality scores, batch history, feedstock and notes, composting method, formation and turning dates, pile temperature and lab sample ID, ready for your own charts or to share with an adviser.

VCAT is priced by facility size: $249/month for facilities under 2,000 tons a year, $499/month from 2,000 to 20,000 tons, and from $1,499/month above that. Every plan includes unlimited assessments, unlimited users, pile and batch history and the web portal, and there's no hardware to buy. Multi-site operators can contact us for a combined quote. See pricing for details.