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BelowGrid

Methodology

How BelowGrid knows what it tells you

An answer here is only as good as the document behind it. So every answer is made from three things, and all three are on the page for you to check.

Last updated 2 October 2026

  • The official document

    Such as a city’s municipal code, a sewer district’s rules, a water supplier’s own pages or a programme’s terms. Every answer links to it.

  • The words it uses

    The sentences that say who looks after which part of the pipe, or what is required, quoted from that document.

  • The date it was checked

    When the document was checked for this answer. Where that was a long time ago, the answer says so beside the date.

If an answer and its document ever disagree, the document is right. How to tell us

From an official document to the answer on your page

Part of the work is done before anyone searches, and part when you enter an address.

Before anyone searches

  1. Find the official document

    For each place BelowGrid covers: the city, county, sewer district or water supplier, usually its own code, rules or programme page.

  2. Quote the words and record the date

    The sentences that say who looks after which length of pipe, and what is required and when, are quoted with the date the document was checked.

When you enter an address

  1. Find the property

    The address is matched to a location. If more than one could be meant, you see the choices and pick one.

  2. Find who governs it

    The location is matched against each authority’s published boundary, not the postal city. A city, a county and a district can all apply, and all are shown.

  3. Check each local rule

    Each requirement is checked against what is known about the property: it applies, it does not, or it cannot be determined from what is known. Where two authorities conflict, that is said instead.

  4. Show the answer beside its source

    Each answer names who stated it and when it was checked, and links to the document so you can read the words yourself.

What each part of a result means

A property page answers for two pipes, the sewer lateral and the water service line, and each answer is laid out the same way.

How one pipe’s answer is laid out, drawn as an example. A real answer uses the authority’s own words, name and date.

  1. The verdict

    The headline, in plain words: where the authority’s document says the owner’s part ends — at the meter, the property line, the curb, the main. “Nobody has put this in writing” means the document does not say, and BelowGrid does not guess either way.

  2. The owner’s part and the authority’s part

    What the document says the property owner looks after, and what the city, district or utility takes on. Read the words: an authority may maintain its part, own it, or repair it only in some cases, and the words say which.

  3. Conditions

    “If certain conditions are met” after a verdict means the split depends on something. What it depends on is given in the authority’s words under “What decides which applies”. Read it before relying on the headline.

  4. Who stated it, and when it was checked

    The authority is named, and can link to its page where it has one. The date is when the document was checked for this answer. Where that check is over a year old — or, for help towards the cost, the terms were confirmed over six months ago — a note beside the date says so.

  5. The source

    A link to the document itself. It is what settles the answer, not the page.

The rest of a property result

Local requirements checked

Each local requirement checked for the property, with when it is triggered — when you sell, when you remodel — and one of three outcomes:

  • Appears to apply
  • Did not apply
  • Could not be determined

Where two authorities conflict, it says Authorities disagree instead. Every rule checked is listed, including the ones that did not apply.

Help towards the cost

Grants, loans and rebates offered by an authority covering the address: who offers it, the amount, who can apply and the official page to apply on. “Confirm before relying on this” sits above the amount where the terms could not be confirmed.

What to do next

Steps taken from the same records as the answers, each with a link to the official source or the authority’s site.

Records found

Records about the property itself, where a covered source holds them. “No matching record found” is a statement about those sources, not about the property. Where BelowGrid has published no record of those kinds for any address, the section says that instead and names them, and the coverage list gives them one line.

No published answer here

BelowGrid holds no answer for that pipe at that address. That is about BelowGrid’s coverage, not about the pipe.

Evidence coverage

How much of the record BelowGrid can see for the property, as a band: excellent, good, partial or limited. It describes the paperwork, not the pipe. How it is worked out

What we don’t do, and what we can get wrong

What BelowGrid does not do

  • It is not an inspection. Nobody has looked at the pipe. BelowGrid reports what official sources record, and records are not the same thing as condition.

  • It is not legal advice. A requirement shown here is reported as the authority states it. Whether it applies to a particular transaction is a question for that authority.

  • It does not rate properties. The coverage label is not a risk score, and it says nothing about the condition of anything underground. A property with excellent coverage may have a failing lateral; a property with limited coverage may be in perfect order.

  • It does not fill gaps with guesses. A missing fact never becomes “this does not apply to you”. Where a rule depends on something BelowGrid does not hold, such as a construction year, the answer is that it cannot be determined. Where it cannot confidently tell which authority governs a property, it says so rather than guessing from the city name.

  • It does not settle disagreements. Where two authorities disagree, both are shown and neither is chosen.

  • It does not cover everything under a property. Septic systems and heating-oil tanks are not covered yet.

Where it can be wrong

  • An absence of records is never good news. When BelowGrid shows nothing, that is a statement about the sources it can see. It is not evidence that nothing exists, and it is never evidence about the property.

  • Most answers have not been read by a person. Most of what is here was researched and written by software working to a fixed method, and for most answers nobody at BelowGrid has read the source document. That is precisely why every claim is quoted and every quotation is linked: the document is the check this site offers, not our sign-off on it. Nothing is published without a source you can open.

  • A document can change after it was checked. Ordinances are amended and programmes close. The date each answer was checked is shown beside it, with a note when that check is old.

  • The wrong property would be the worst mistake. Choosing the wrong match would show somebody else’s property, so where more than one address could be meant, you choose. Where the property or its service provider is uncertain, the coverage label is held down to say so.

  • An answer can simply be wrong. If the document says something different from the page, the document is right.

When BelowGrid is wrong

It will be, and the honest thing is to say how you can tell. Every statement links to the document it came from. If the document says something different, the document is right.

Report it and it will be checked against the source.

Report a correction

What makes a report quick to check

  1. The page. Its address, or the place and requirement it concerned.

  2. What is wrong. What the page says, and what it should say.

  3. Where you saw otherwise. A link to the ordinance, the programme page or the record. This matters most.

The detail

For readers who want to know exactly how each step works.

How an address is matched

A submitted address is matched against a geocoding provider and, where more than one candidate is plausible, the choice is presented rather than made. Choosing wrongly would show somebody else’s property, which is the most damaging error this product can make.

The chosen candidate is carried forward by identifier, never by re-parsing the text that was typed.

How the governing authorities are found

Every authority is resolved by a spatial match against its published boundary, not by the postal city on an address. Sewer service areas and municipal lines do not agree, and a postal city is often neither.

A property sits under several authorities at once: a city, a county, sometimes a regional programme. Each may impose its own requirements, so all of them are resolved and all of them are shown.

Boundaries come from the U.S. Census Bureau TIGER/Line files.

How rules are checked

Rules are evaluated with three outcomes rather than two: applies, does not apply, and cannot be determined — and, where two authorities conflict, a fourth label saying so. Where a rule depends on a fact BelowGrid does not hold — a construction year, a use class — the answer is that it could not be confirmed.

Where two authorities disagree, BelowGrid reports a conflict; it does not resolve one. The result says to confirm with each authority, because which requirement takes precedence is not something the published sources settle.

What the coverage label measures

Coverage measures how much of the record BelowGrid can see for a property.

Eight categories are weighted and summed. Where the identity of the property or its service provider is uncertain, the score is capped rather than reduced — a high score assembled against a possibly-wrong authority invites confidence the evidence does not support.

The label is a band rather than a number, because a number reads as precision the underlying data does not have. Every category is listed on the page, including the ones with nothing in them.

How evidence is attached

A finding cannot exist without a source. That is built into the system itself, not left to editing: there is no path that produces an unsourced claim about a property.

Findings are distinguished by kind. “A rule applies to properties like yours” is shown differently from “here is a record about your property”, because they are different claims.