How the Trust Rating works

Every septic company listed on Best Septic Companies that has a Google rating on file gets a Trust Rating from 0 to 100. It's a computed score, not a manual opinion, and it's built entirely from information we actually hold about a listing. The sections below cover what goes into it, what doesn't, and why.

What the Trust Rating is not: it is not a license check, not an inspection, not a background check, and not a measure of how fast a company responds to a call. We don't hold any of that data, so none of it factors into the score. See what we don't measure below.

The three inputs, and their weight

The score is a weighted combination of three things, all sourced from public business information (Google ratings and review counts) and each listed company's own website:

1. Rating quality (50% of the score)

We use each company's Google star rating, but we don't take it at face value. A 5.0 rating built on 2 reviews is weaker evidence than a 4.7 rating built on 150 reviews, so we apply a standard statistical adjustment (Bayesian shrinkage) that pulls low-review-count ratings toward the average rating across our whole directory until more reviews come in. In plain terms, a handful of five-star reviews alone won't outscore a large base of strong reviews.

2. Review volume (25% of the score)

Separately from the rating value itself, we credit how many reviews that rating is based on. More reviews means more people's experience is reflected in the number, which is itself useful information. This component increases with review count but levels off, so a company with a few hundred reviews and a company with a few thousand aren't meaningfully different on this measure.

3. Service-information completeness (25% of the score)

We track a fixed set of septic service types (pumping, installation, emergency and weekend availability, drain-field repair, aerobic system service, real-estate inspections, grease trap service, and riser installation) and check each company's own website for evidence of each one. This component reflects how many of those services appear in the source material. It is a measure of how much service information we hold, not a ranking of how much work a company does or a claim about which company is "better."

What we don't measure

We deliberately leave the following out of the score, because we don't have the data to back it up and we'd rather show nothing than invent something:

Licensing. Septic licensing is issued state by state, and often county by county in the US. License lookup is not an input in this score.
Response time. Some competitor sites claim a response-time score. We don't collect real dispatch or call-response data, so we don't publish a number for it. Don't take a fast-response claim on this site at face value either, because you won't find one here.
An inspection or background check. We have not visited, audited, or vetted any listed company. The Trust Rating summarizes public information, not a review we performed.
Pricing. Price does not factor into the score. See our cost guides for typical price ranges instead.

Reading the score

Scores fall into four bands, shown as the color of the badge:

85 to 100, Strong profile: a well-established rating history plus most or all tracked services confirmed.
65 to 84, Established profile: solid rating history with a reasonable number of confirmed services.
40 to 64, Developing profile: a newer or thinner rating history, or fewer services confirmed from the company's website.
Below 40, Limited profile data: little to go on yet. A low score usually reflects a small review count or a website that doesn't state much about its services, not necessarily a poor company.
Not enough data yet: shown instead of a number when a listing has no Google rating on file. We never assign a fabricated score to fill the gap.

A low or missing score is not a red flag on its own; it usually just means less public information exists for that company yet.

The "Full-service septic provider" label

Separately from the numeric score, a listing earns a "Full-service septic provider" label when its website confirms three or more service types beyond routine pumping (for example: installation, drain-field repair, aerobic system service, real-estate inspections, grease trap service, riser installation, emergency or weekend availability). Like the Trust Rating, this is computed automatically from the same enriched attribute data, not assigned by hand.

When the score updates

The Trust Rating is recalculated whenever we refresh our underlying data (ratings, review counts, and service information). We don't hand-adjust an individual company's score up or down.

Browse the full directory to see Trust Ratings on listed companies, or tell us what you need and we'll pass your enquiry along.