Editorial
How this site is written, checked, and corrected
Cost and code content is worth exactly as much as its sourcing. Here is ours — including the parts we could not verify.
Who is responsible for this content
Editorial responsibility sits with the New Septic System Cost editorial team, which researches, writes, and re-verifies every page on this site. We are not a contractor, a manufacturer, or a lead broker, and no outside party reviews or approves what is published here.
Corrections and questions about sourcing go to corrections@newsepticsystemcost.com or through the contact page. We read all of them.
Where the numbers come from
There are three kinds of number on this site and they are sourced differently. Knowing which is which is the difference between using a figure and being misled by it.
1. Regulatory figures — cited to the rule
Tank minimums, design flow per bedroom, detention multiples, setbacks, and reserve-area requirements are read from each state's own administrative code or the health department's published rule. All 50 states carry a sources list — 99 citations in total — each with the document title, a link, and the date it was last checked. If a figure on a state page has no citation behind it, that is a bug; tell us.
2. Engineering outputs — computed, and the method is published
Drainfield area, trench layout, pumping intervals, and rated design flow are calculated, not looked up. The model is a single pure module, unit tested, and the assumptions behind it — EPA 625/R-00/008 Table 4-7 loading rates, the extension-service solids-accumulation equation, the stock tank sizes actually manufactured — are documented on the methodology page. Every calculator shows which rule governed its answer so you can check the working rather than trust the output.
3. Cost ranges — researched estimates, labelled as estimates
Installed-cost ranges are the softest numbers here and we treat them that way. They come from published contractor pricing, state cost-of-construction indices, and permit fee schedules, expressed as ranges rather than point estimates because that is what the underlying data honestly supports. A cost figure on this site is a planning number for comparing bids. It is not a quote and we never present it as one.
What we do when we cannot verify something
Several states publish their sizing tables only as scanned images that cannot be read reliably. In those cases the figure goes into an unverified list and the state page tells you so, in place of the number. We would rather show a gap than a plausible guess, because a plausible guess is indistinguishable from a fact once it is on the page.
How often it is re-checked
The full state dataset was last verified end to end on . Each state page carries its own per-source verification dates, which are the ones that matter — a state that amended its code last month is more urgent than one that has not changed since 2015. Guides carry an updated date in the same way.
Our sitemap reports those real dates. It does not stamp every page with the build timestamp, which would tell search engines the entire site changed every time we deploy a CSS fix.
Corrections
If a figure here does not match what your health department told you, your health department is right. That is not false modesty — they are the permitting authority and we are a reference. Send us what they said and we will check the source, fix the page, and update the verification date.
When we correct something material, we change the figure and move the verification date. We do not quietly edit a number and leave the old date in place.
Independence and money
New Septic System Cost sells nothing. No tanks, no systems, no installation, no inspections. We take no contractor referral fees and we do not operate or sell into a lead marketplace. Nothing on this site is gated behind an email address, and no page's recommendation has ever been shaped by who pays for the click — because nobody does.
If that changes, this page changes first, and any commercial relationship will be disclosed on the pages it touches before it affects a single recommendation.
What this site is not
- Not a permit. Your county can be stricter than your state, and often is.
- Not an engineering design. A site evaluation can change every number on a page.
- Not a quote. Only a contractor who has walked your site can give you one.
The full limitations are on the disclaimer, and the technical detail is on the methodology page.