Evidence register

See what supports every safety claim.

DrainPath uses official federal, local-government, and public-utility material to set conservative safety boundaries. This register shows the original source, the claim it supports, where we use it, and what it cannot prove.

Official sources: 23
Claim boundaries: 15
Public agencies: 13
Last reviewed: July 25, 2026

How to read this register

Evidence for triage, not a remote diagnosis.

“Supports” means a source is adequate for the narrow statement shown here. It does not mean the source endorses DrainPath, applies to every jurisdiction, or confirms the cause of a specific home's symptoms.

Local code, utility ownership, product labels, and site conditions can change the right response. When a source is local or has a limited scope, that limitation is stated alongside it.

Claim coverage

The evidence map

Each stable claim ID can be used by the symptom checker, safety guidance, and editorial review without silently changing the meaning of its evidence.

sewage_backup4 sources

Sewage backup and exposure

Untreated sewage can contain pathogens. A suspected backup warrants stopping water use, avoiding contact, and escalating to the appropriate utility or professional.

Evidence boundaryThe sources support precautionary action, not a remote determination of contamination level or cleanup clearance.

Sanitary Sewer Overflow (SSO) Frequent QuestionsA sanitary sewer overflow releases untreated or partially treated sewage and can create public-health risk through pathogens and direct contact.
Sewer Backup? Call Us FirstThe utility lists sewage entering a tub or shower and water rising from a floor drain as warning signs and advises stopping water use and keeping people and pets away.
Returning Home After a Natural DisasterContaminated floodwater can contain germs and chemicals, supporting a precautionary no-contact approach when water is of unknown origin.
Resolving Septic System MalfunctionsSewage exposure should be avoided and malfunction response may require protective measures and local health or environmental authorities.

wet_electrical3 sources

Water near electrical equipment

Do not enter standing water to reach electrical controls or use powered equipment while standing in water.

Evidence boundaryOnly the utility or a qualified electrician can determine whether equipment is safe to energize.

What to Do to Protect Yourself From Electrical HazardsA person should not enter standing water to reach the main power switch or use electrical tools or appliances while standing in water.
Returning Home After a Natural DisasterWet electrical systems and standing water require precautions before power is turned on or equipment is used.
Septic Systems — What to Do After the FloodFlooded septic equipment can include electrical hazards that should be handled by trained specialists.

chemical_use7 sources

Chemical drain-product safety

Drain openers may be corrosive or otherwise hazardous. Labels matter, leftovers should not be mixed, and disposal rules vary.

Evidence boundaryNo universal instruction is safe for every product or for a drain after an unknown chemical has already been used.

Household Hazardous Waste (HHW)Some household products can be corrosive, reactive, ignitable, or toxic; users should follow labels and never mix leftover products.
Household Hazardous Waste and DemolitionDrain openers are listed among household hazardous wastes that should not be poured into drains or storm sewers.
Guidance for Hazard Determination for Compliance with the OSHA Hazard Communication StandardStrong alkalis, including sodium and potassium hydroxide, are corrosive and can severely damage skin, eyes, and mucous membranes.
Sodium HydroxideSodium hydroxide is also identified as lye or caustic soda and carries a serious health-hazard rating.
Drain Cleaners Recalled Due to Failure to Meet Child-Resistant Packaging Requirement; Risk of Poisoning and Chemical BurnsA recalled 100% sodium-hydroxide drain cleaner presented poisoning and chemical-burn risks when required packaging and warnings were missing.
Returning Home After a Natural DisasterBleach and other cleaners should not be mixed because dangerous fumes can result.
Septic Tank AdditivesChemical treatment choices can affect pipes, tanks, system components, and septic bacteria.

septic_system4 sources

Septic-system constraints

Septic systems require different disposal and maintenance choices; drain cleaners, grease, and unsupported additives can create risk.

Evidence boundarySymptoms do not establish the condition of a tank, drainfield, pump, or line without inspection.

Household Hazardous Waste (HHW)Disposal through a drain or toilet can affect septic tanks or wastewater-treatment systems.
Frequent Questions on Septic SystemsEPA advises keeping grease, drain cleaners, household chemicals, and other unsuitable materials out of septic systems and does not recommend routine additives.
Resolving Septic System MalfunctionsBackups, slow fixtures, gurgling, odors, and wet areas can indicate septic-system malfunction.
Septic Tank AdditivesEPA does not recommend septic-tank additives and warns that strong acid or alkali cleaners may harm system biology or components.

multiple_fixtures3 sources

Multiple affected fixtures

Several drains slowing, gurgling, or backing up together can indicate a shared line or system problem rather than an isolated fixture clog.

Evidence boundaryThe pattern narrows scope but does not identify the exact obstruction location or ownership.

Sewer Backup? Call Us FirstSeveral drains backing up or making unusual gurgling sounds are listed as backup warning signs.
If You Have a Plumbing BlockageThe authority says all drains backing up at once is more consistent with a main sewer-line problem than a single-fixture blockage.
Frequent Questions on Septic SystemsSlow drains, gurgling, and plumbing backups can be signs of a malfunctioning septic system.

venting_trap_seal3 sources

Vent and trap-seal function

Plumbing vents balance pressure and traps retain a liquid seal; failures can contribute to gurgling or odors.

Evidence boundaryCode provisions explain system function. They do not prove that a particular home has a vent blockage or dry trap.

Frequent Questions on Septic SystemsEPA notes that indoor septic odor can also relate to a dry drain trap or a roof-vent condition.
24 CFR § 3280.602 — DefinitionsThe regulation defines a trap liquid seal, siphonage, and a venting system that circulates air through drainage piping.
New York City Plumbing Code § PC 901.2 — Trap Seal ProtectionThe code describes vent piping as admitting or emitting air so pressure changes do not compromise fixture-trap seals.

gas_hydrogen_sulfide2 sources

Gas odor and hydrogen sulfide

Odor can signal very different hazards. Odorized natural gas requires immediate evacuation precautions, while hydrogen sulfide can occur around sewage and smell is not a reliable exposure meter.

Evidence boundaryA website cannot identify a gas by odor, rule out danger, or tell a user to investigate the source.

Pipeline Emergency ResponseA distinctive sulfur-like odor may be odorized natural gas; suspected pipeline gas requires leaving the area and avoiding flames, engines, phones, and electrical switches until safely away.
NIOSH Pocket Guide to Chemical Hazards — Hydrogen SulfideHydrogen sulfide is also called sewer gas, can smell like rotten eggs, and can rapidly fatigue the sense of smell, so odor cannot reliably indicate continued presence.

public_sewer_signal2 sources

Possible public-sewer involvement

A utility may need to check its main when several fixtures or nearby properties show backup symptoms.

Evidence boundaryUtility responsibility and the correct first call differ by municipality.

Sewer Backup? Call Us FirstThe utility can check whether its sewer main is blocked before private work proceeds.
If You Have a Plumbing BlockageThe authority directs customers to contact it when the pattern may involve the main sewer line.

private_lateral2 sources

Possible private-lateral involvement

The building sewer or lateral can be privately maintained even when it connects to a public sewer.

Evidence boundaryThe public/private boundary is local; the cited municipal examples are not nationwide ownership rules.

Sewer Backup? Call Us FirstThe page distinguishes a city-main problem from a private sewer-lateral problem.
If You Have a Plumbing BlockageA single affected fixture is presented as more likely to need a plumber for private plumbing.

remote_diagnosis_limit6 sources

Remote-diagnosis limit

Symptom patterns can suggest a safer next step, but locating a blockage or confirming a failed component generally requires local inspection.

Evidence boundaryResults must remain triage guidance and must not be presented as a diagnosis, clearance, or code determination.

Sewer Backup? Call Us FirstOn-site utility investigation is used to distinguish public-main and private-lateral causes.
If You Have a Plumbing BlockageThe recommended next party depends on the observed pattern and follow-up investigation.
Frequent Questions on Septic SystemsThe same symptom can have more than one cause, and system condition may require a qualified service provider.
Resolving Septic System MalfunctionsEPA directs owners toward trained service providers and the local permitting authority to evaluate and correct malfunctions.
Septic Systems — What to Do After the FloodCleaning and repair after flooding should be performed by trained septic-system specialists.
NIOSH Pocket Guide to Chemical Hazards — Hydrogen SulfideOdor alone cannot identify or quantify hydrogen-sulfide exposure.

fats_oils_grease3 sources

Fats, oils, and grease

FOG can cool and accumulate in pipes, contributing to blockages, backups, odor, and sewer-system damage.

Evidence boundaryPrevention guidance does not establish that grease caused a specific active backup.

Sanitary Sewer Overflow (SSO) Frequent QuestionsFats, oils, grease, wipes, and roots are among causes of sanitary-sewer blockages.
Fats, Oils & Grease (FOG)The utility identifies FOG as a leading source of sewer blockage and links buildup to reduced capacity, odors, backups, and damage.
Fats, Oils and GreaseFOG can cool and harden in sewer pipes, create blockages, and contribute to backups; used cooking oil and grease should be collected rather than poured down drains.

powered_auger_cross_bore1 source

Powered auger and cross-bore risk

A gas line can unknowingly intersect a sewer line; a rotating auger used on that sewer can damage the gas line and cause a leak.

Evidence boundaryThe source establishes a serious possible hazard, not the prevalence of cross bores at a particular property.

Gas Distribution Integrity Management Program: Resources — Cross BoresA gas line installed through an existing sewer can remain unnoticed until a rotating auger damages it while clearing a blockage, causing a gas leak.

septic_flood_response1 source

Flooded septic-system response

A flooded or saturated septic system should be used sparingly and evaluated after water recedes; pumping during saturation can cause damage.

Evidence boundarySoil saturation, tank condition, and safe restoration timing require local evaluation.

Septic Systems — What to Do After the FloodEPA advises reducing water use and not pumping a septic tank while the soil remains saturated or flooded.

roof_access1 source

Roof and ladder access

Ladder and roof work introduces a fall hazard, so remote guidance should not direct an untrained resident onto a roof to inspect a vent.

Evidence boundaryGeneral ladder guidance does not certify any setup, roof, weather condition, or person as safe.

Ladder SafetyLadder falls cause serious injuries at work and at home, supporting a conservative boundary against directing users onto roofs.

backflow_prevention1 source

Sewer backflow prevention

A properly selected backwater valve can reduce sewer backflow risk when installed as part of a property-specific mitigation plan.

Evidence boundaryA valve is preventive equipment, not a remedy for an active backup, and selection is subject to local code and professional design.

Protect Your Home From FloodingA sewer backflow valve can help prevent wastewater from entering through connected fixtures and should be addressed with a qualified, licensed plumber.

Original material

Official source register

Every external link goes to the original government or public-utility page reviewed onJuly 25, 2026.

Last reviewed: July 25, 2026
Source date: Page updated June 1, 2026
Jurisdiction: United States — federal guidance

Supported claims

chemical_useSome household products can be corrosive, reactive, ignitable, or toxic; users should follow labels and never mix leftover products.
septic_systemDisposal through a drain or toilet can affect septic tanks or wastewater-treatment systems.

Used in

Limits

The page does not evaluate a specific drain-cleaner formula or give post-exposure medical advice.
Collection and disposal options are local.

Last reviewed: July 25, 2026
Source date: Page updated March 9, 2026
Jurisdiction: United States — federal guidance

Supported claims

chemical_useDrain openers are listed among household hazardous wastes that should not be poured into drains or storm sewers.

Used in

Limits

Written for residential demolition waste handling, not for clearing an active clog.
Local household-hazardous-waste programs set acceptance rules.

Last reviewed: July 25, 2026
Source date: Guidance document; no current revision date displayed
Jurisdiction: United States — federal workplace guidance

Supported claims

chemical_useStrong alkalis, including sodium and potassium hydroxide, are corrosive and can severely damage skin, eyes, and mucous membranes.

Used in

Limits

This is workplace hazard-classification guidance, not consumer product instructions.
Hazard severity for a product depends on its actual ingredients and concentration.

Last reviewed: July 25, 2026
Source date: Chemical profile updated October 10, 2024
Jurisdiction: United States — federal workplace data

Supported claims

chemical_useSodium hydroxide is also identified as lye or caustic soda and carries a serious health-hazard rating.

Used in

Limits

The chemical profile does not show whether a particular product contains sodium hydroxide.
It does not replace a product label, Safety Data Sheet, poison-control advice, or emergency care.

Last reviewed: July 25, 2026
Source date: Recall published March 18, 2020
Jurisdiction: United States — federal product-safety enforcement

Supported claims

chemical_useA recalled 100% sodium-hydroxide drain cleaner presented poisoning and chemical-burn risks when required packaging and warnings were missing.

Used in

Limits

This recall applies to named products and packaging, not to every drain cleaner.
Recall evidence cannot be generalized into directions for an unknown product.

Last reviewed: July 25, 2026
Source date: Page updated April 13, 2026
Jurisdiction: United States — federal guidance

Supported claims

sewage_backupA sanitary sewer overflow releases untreated or partially treated sewage and can create public-health risk through pathogens and direct contact.
fats_oils_greaseFats, oils, grease, wipes, and roots are among causes of sanitary-sewer blockages.

Used in

Limits

The page describes sanitary-sewer systems and overflows; it cannot classify liquid in a home remotely.
It does not assign responsibility for a particular building lateral.

Last reviewed: July 25, 2026
Source date: No update date displayed; live page checked July 25, 2026
Jurisdiction: Roseville, California — local utility guidance

Supported claims

sewage_backupThe utility lists sewage entering a tub or shower and water rising from a floor drain as warning signs and advises stopping water use and keeping people and pets away.
multiple_fixturesSeveral drains backing up or making unusual gurgling sounds are listed as backup warning signs.
public_sewer_signalThe utility can check whether its sewer main is blocked before private work proceeds.
private_lateralThe page distinguishes a city-main problem from a private sewer-lateral problem.
remote_diagnosis_limitOn-site utility investigation is used to distinguish public-main and private-lateral causes.

Used in

Limits

Phone number, response process, and ownership boundaries apply to Roseville customers.
Other users must check their own wastewater utility's rules.

Last reviewed: July 25, 2026
Source date: No update date displayed; live page checked July 25, 2026
Jurisdiction: Simsbury, Connecticut — local utility guidance

Supported claims

multiple_fixturesThe authority says all drains backing up at once is more consistent with a main sewer-line problem than a single-fixture blockage.
public_sewer_signalThe authority directs customers to contact it when the pattern may involve the main sewer line.
private_lateralA single affected fixture is presented as more likely to need a plumber for private plumbing.
remote_diagnosis_limitThe recommended next party depends on the observed pattern and follow-up investigation.

Used in

Limits

This is a local triage process, not a national ownership standard.
The words “more likely” describe a pattern, not a diagnosis.

Last reviewed: July 25, 2026
Source date: Page dated February 9, 2024
Jurisdiction: United States — federal public-health guidance

Supported claims

wet_electricalA person should not enter standing water to reach the main power switch or use electrical tools or appliances while standing in water.

Used in

Limits

The page is disaster-response guidance and does not inspect a home's wiring or equipment.
Power isolation and restoration may require the utility or a qualified electrician.

Last reviewed: July 25, 2026
Source date: Page updated April 30, 2026
Jurisdiction: United States — federal public-health guidance

Supported claims

wet_electricalWet electrical systems and standing water require precautions before power is turned on or equipment is used.
sewage_backupContaminated floodwater can contain germs and chemicals, supporting a precautionary no-contact approach when water is of unknown origin.
chemical_useBleach and other cleaners should not be mixed because dangerous fumes can result.

Used in

Limits

Floodwater is not synonymous with a sanitary-sewer backup.
Disaster cleanup instructions do not establish that an indoor drain event is safe to clean without local assessment.

Last reviewed: July 25, 2026
Source date: Page updated March 11, 2026
Jurisdiction: United States — federal guidance

Supported claims

septic_systemEPA advises keeping grease, drain cleaners, household chemicals, and other unsuitable materials out of septic systems and does not recommend routine additives.
multiple_fixturesSlow drains, gurgling, and plumbing backups can be signs of a malfunctioning septic system.
venting_trap_sealEPA notes that indoor septic odor can also relate to a dry drain trap or a roof-vent condition.
remote_diagnosis_limitThe same symptom can have more than one cause, and system condition may require a qualified service provider.

Used in

Limits

The page lists warning signs and possibilities; it does not diagnose a component.
State and local septic requirements vary.

Last reviewed: July 25, 2026
Source date: Page updated March 11, 2026
Jurisdiction: United States — federal guidance

Supported claims

sewage_backupSewage exposure should be avoided and malfunction response may require protective measures and local health or environmental authorities.
septic_systemBackups, slow fixtures, gurgling, odors, and wet areas can indicate septic-system malfunction.
remote_diagnosis_limitEPA directs owners toward trained service providers and the local permitting authority to evaluate and correct malfunctions.

Used in

Limits

Warning signs overlap with ordinary plumbing problems.
Repair and permitting decisions are property- and jurisdiction-specific.

Last reviewed: July 25, 2026
Source date: Page updated September 3, 2025
Jurisdiction: United States — federal guidance

Supported claims

septic_flood_responseEPA advises reducing water use and not pumping a septic tank while the soil remains saturated or flooded.
wet_electricalFlooded septic equipment can include electrical hazards that should be handled by trained specialists.
remote_diagnosis_limitCleaning and repair after flooding should be performed by trained septic-system specialists.

Used in

Limits

This guidance applies when a septic system or its soil area has flooded or saturated.
It cannot determine remotely when a particular site is dry or structurally sound.

Last reviewed: July 25, 2026
Source date: EPA 830-F-24-003, September 2024
Jurisdiction: United States — federal guidance

Supported claims

septic_systemEPA does not recommend septic-tank additives and warns that strong acid or alkali cleaners may harm system biology or components.
chemical_useChemical treatment choices can affect pipes, tanks, system components, and septic bacteria.

Used in

Limits

The fact sheet addresses septic systems, not the performance of a named drain product.
It does not establish that one household use caused a particular failure.

Last reviewed: July 25, 2026
Source date: No update date displayed; live page checked July 25, 2026
Jurisdiction: Salt Lake City, Utah — local utility guidance

Supported claims

fats_oils_greaseThe utility identifies FOG as a leading source of sewer blockage and links buildup to reduced capacity, odors, backups, and damage.

Used in

Limits

Disposal instructions and utility enforcement are local.
The page supports prevention guidance, not a diagnosis of an active clog.

Last reviewed: July 25, 2026
Source date: No update date displayed; live page checked July 25, 2026
Jurisdiction: Fairfax County, Virginia — local government guidance

Supported claims

fats_oils_greaseFOG can cool and harden in sewer pipes, create blockages, and contribute to backups; used cooking oil and grease should be collected rather than poured down drains.

Used in

Limits

Collection options and disposal requirements are local.
The guidance does not locate or characterize a current blockage.

Last reviewed: July 25, 2026
Source date: Live resource page checked July 25, 2026
Jurisdiction: United States — federal pipeline-safety guidance

Supported claims

powered_auger_cross_boreA gas line installed through an existing sewer can remain unnoticed until a rotating auger damages it while clearing a blockage, causing a gas leak.

Used in

Limits

The page establishes a possible cross-bore mechanism, not its likelihood at an address.
It does not authorize a particular sewer-clearing method or contractor.

Last reviewed: July 25, 2026
Source date: Live federal safety page checked July 25, 2026
Jurisdiction: United States — federal pipeline-safety guidance

Supported claims

gas_hydrogen_sulfideA distinctive sulfur-like odor may be odorized natural gas; suspected pipeline gas requires leaving the area and avoiding flames, engines, phones, and electrical switches until safely away.

Used in

Limits

This source concerns pipeline natural gas, not diagnosis of sewer gas or hydrogen sulfide.
Odor descriptions overlap; users should not investigate a suspected gas source.

Last reviewed: July 25, 2026
Source date: Live chemical profile checked July 25, 2026
Jurisdiction: United States — federal occupational-health guidance

Supported claims

gas_hydrogen_sulfideHydrogen sulfide is also called sewer gas, can smell like rotten eggs, and can rapidly fatigue the sense of smell, so odor cannot reliably indicate continued presence.
remote_diagnosis_limitOdor alone cannot identify or quantify hydrogen-sulfide exposure.

Used in

Limits

The pocket guide is an occupational chemical reference, not a residential air test.
A sulfur-like odor does not prove hydrogen sulfide and does not rule out natural gas.

Last reviewed: July 25, 2026
Source date: Current eCFR display checked July 25, 2026
Jurisdiction: United States — federal manufactured-home standard

Supported claims

venting_trap_sealThe regulation defines a trap liquid seal, siphonage, and a venting system that circulates air through drainage piping.

Used in

Limits

This section applies to manufactured homes within the federal standard's scope.
Definitions explain function but do not diagnose gurgling, odor, or a blocked vent.

Last reviewed: July 25, 2026
Source date: Online code text checked July 25, 2026
Jurisdiction: New York City — local plumbing code

Supported claims

venting_trap_sealThe code describes vent piping as admitting or emitting air so pressure changes do not compromise fixture-trap seals.

Used in

Limits

This is New York City code, not a nationwide residential rule.
A functional description does not establish the cause of a symptom in a particular building.

Last reviewed: July 25, 2026
Source date: Page dated January 23, 2024
Jurisdiction: United States — federal safety guidance

Supported claims

roof_accessLadder falls cause serious injuries at work and at home, supporting a conservative boundary against directing users onto roofs.

Used in

Limits

General ladder-safety information does not certify a particular ladder, roof, user, or weather condition.
It does not provide plumbing-vent inspection instructions.

Last reviewed: July 25, 2026
Source date: Federal mitigation brochure; 2020 edition checked July 25, 2026
Jurisdiction: United States — federal mitigation guidance

Supported claims

backflow_preventionA sewer backflow valve can help prevent wastewater from entering through connected fixtures and should be addressed with a qualified, licensed plumber.

Used in

Limits

The brochure is mitigation guidance, not approval for a specific installation.
Valve type, maintenance, code compliance, and effectiveness are property-specific.

Maintenance

Review policy

We re-check the original URL, issuing agency, relevant language, and stated scope before relying on a source. A review date records that check; it is not the source's publication date.

If an original page moves or its guidance changes, the affected claim should be held for editorial review until its evidence and wording are reconciled.