What this is
What is a drain register?
What is a drain register?
A drain register is a record of every drain on a site, where each one discharges to, and what may legitimately enter it. It underpins every other spill and pollution prevention record, because deciding how to respond to a release depends entirely on knowing whether the nearest drain leads to treatment, a sewer, or a watercourse.
Why does it matter whether a drain is foul or surface water?
A foul drain carries wastewater to a treatment works built to handle contamination; a surface water drain carries rainwater, usually with little or no treatment, direct to a sewer, an interceptor or a watercourse. The same spill volume down each one produces a very different outcome, which is why the register records the distinction per drain rather than assuming it from the drain's appearance.
What is a cross-connection and why does it matter here?
A cross-connection is a pipe run that has been plumbed to the wrong system, most often a foul discharge finding its way into the surface water network or the reverse. It is a known and common as-built defect, invisible from the surface, and the register's confidence in what a drain does depends on whether the connection has actually been tested rather than assumed from a drawing.
Scope
When is a drain register required?
This register is one step in the spill and pollution prevention programme. Using it to record an actual release, a response, or a regulator notification, rather than the underlying drainage map, produces records that are hard to report on later.
Use this template when
- The site is being set up in the programme for the first time and its drainage needs mapping
- A drain is added, relocated or decommissioned following construction or a site change
- The periodic review of the register falls due
- A spill or drill exposes a gap between the register and the drainage actually on the ground
- A linked record, such as a spill response or containment inspection, needs a verified drain to point to
Do not use it for
- Spill Report, which records an actual release of chemical, fuel, oil or wastewater.
- Spill Response Record, which records what was done to contain, clean up and dispose of a spill.
- Environmental Notification Record, which records what was reported to a regulator, when and by whom.
- Stormwater Outfall Inspection, which inspects the condition and discharge quality of an outfall on a schedule, rather than mapping it.
- Containment Inspection, which inspects the condition of containment and interceptor infrastructure, not the drainage layout itself.
Compliance mapping
Which EPA requirements does this satisfy?
Discharge to a sewer or a watercourse is closely regulated wherever it happens; knowing which pipe on site leads where is treated as basic due diligence for a permit holder, not an optional extra.
| Clause | Requirement | Where it lands |
|---|---|---|
| 40 CFR 122.26 | Industrial stormwater discharge permit programme requires identifying discharge points, drainage area and receiving water for each outfall | Drains |
| Water Industry Act 1991 s.118 | Trade effluent consent required from the sewerage undertaker before discharge to the public sewer | Drains |
| Local sewer bylaws | Foul drainage may discharge only to treatment, not direct to a watercourse, and sets what may lawfully enter each system | Drains |
| 40 CFR 122.26 | Illicit and cross connections between process or sanitary drainage and the stormwater system must be identified and eliminated | Register health |
| 40 CFR 122.26 | The site drainage map must be kept current when discharge points or drainage layout change | Header |
| ISO 14001:2015 cl.6.1.2 | Environmental aspects, including discharge points and drainage routing, identified and kept under control | Register health |
What it does not cover
- Spill Report, which records that a release actually happened, its substance, quantity and location.
- Spill Response Record, which records the containment, clean-up and disposal actions taken during a response.
- Environmental Notification Record, which records what was reported to an environmental regulator, when and by whom.
- Stormwater Outfall Inspection, which inspects an outfall's physical condition and discharge quality on a recurring schedule.
- Containment Inspection, which inspects bunds, interceptors and containment infrastructure rather than mapping the drainage network.
Global
Drain Register requirements by country
The duty to know and control what discharges from a site is close to universal for anyone holding an environmental permit; what differs is whether a drainage map is an explicit permit condition or an implicit expectation behind a broader duty.
40 CFR 122.26, NPDES stormwater discharge programme
Industrial stormwater permits, including general permits, require a site map identifying outfalls, drainage areas and receiving waters, kept current as conditions change.
An out-of-date site map is a compliance gap on its own, independent of whether an exceedance has occurred.
Water Industry Act 1991 s.118 and the Environmental Permitting Regulations 2016
A trade effluent consent is required before discharging to the public sewer, and a permit is required for discharge to controlled waters.
Without a verified register, an operator cannot show which consent or permit applies to which drain, the first thing a regulator asks after an incident.
ISO 14001:2015 cl.6.1.2
Environmental aspects, which include discharge points, must be identified as part of the management system and linked to applicable legal requirements.
Auditors treat an unverified or incomplete register as evidence the aspect identification itself was not done properly, not as a paperwork gap.
How to complete it
How to complete a drain register, step by step
The register looks like a data-entry exercise. The judgement calls below are what decide whether it can actually be trusted the day a spill reaches a drain.
As-built drawings describe intent, not outcome, and neither captures what a contractor changed last month. The verified-by and last-verified fields exist because a register transcribed from paper without a physical walk carries the drawing's own errors.
Marking a drain on the ground matters because nobody has time to trace pipework during an active spill. Coding that has faded, been painted over, or was never applied removes the one control that works at the speed a spill actually moves.
A pipe run plumbed to the wrong system is invisible from the surface and common enough to assume exists on an older site. Dye testing, not inspection, is what confirms a drain does what the register says.
Recording that a penstock or valve exists answers the wrong question. What matters during a spill is whether someone can reach and operate it in time, which is why accessibility is scored separately from presence.
What auditors find
Most common drain register findings
Findings on a drain register are unusual in that the document almost always exists in some form. What an audit finds is how much of it has actually been verified against the site rather than copied from a drawing.
| Finding | Clause | What fixes it |
|---|---|---|
| Register not verified against a physical walk of the site; based on an old drawing only. | 40 CFR 122.26 | Walk and verify every drain, and record the last-verified date and who carried it out. |
| Drains not colour-coded on the ground, or coding faded and never renewed. | Standard-specific | Recolour to the site standard and record the number of drains still without coding. |
| Surface water drain located beside a chemical or fuel storage area with no compensating isolation. | Local sewer bylaws | Install isolation or relocate the storage, and raise an action against the drain record. |
| Cross-connection suspected between foul and surface water systems, with no dye testing performed. | 40 CFR 122.26 | Commission dye or CCTV testing, correct any confirmed cross-connection, and update the register. |
| No trade effluent consent recorded for a drain discharging to the municipal sewer, or consent status unknown. | Water Industry Act 1991 s.118 | Confirm consent status with the sewerage undertaker and record it against the specific drain. |
| Isolation point exists on the register but is inaccessible or obstructed in practice. | Standard-specific | Clear access to the isolation point and verify it during the next walk before sign-off. |
Case in point
Case in point: the gully that was foul on paper and surface water on the ground
A distribution yard's drain register, inherited from the site's original construction drawings, showed a gully near the fuel delivery point as connected to the foul sewer. The register had never been dye tested; it had only ever been transcribed when the site changed operators.
A coupling failure during a routine delivery sent diesel into that gully. Responders assumed foul routing and treated it as a contained, low-urgency event, only to be told twenty minutes later by the water utility that the gully in fact discharged, via an undocumented cross-connection, direct to a stream. The corrective action was not a better spill response; it was a full dye-test verification of every drain on the register before it was trusted again.
The template
The template, field by field
The form exactly as it installs. Every field, option, score and conditional rule is editable, and the links to other templates come with it.
3 sections
- Reference
- ENV-006
- Archetype
- Register
- Record ID
- DRN-2026-000
- Scoring
- Not scored
- Direction
- n/a
- Singleton
- No
- Basis
- EPA, local sewer bylaws
- Links
- Links Site
- Tags
- Environment, Master data
- Sections
- 3
- Fields
- 37
- Follow up fields
- 3
- Repeating sections
- 1
- Links out
- 3
Header
8 fieldsRegister ID*
Auto sequence. Format DRN-2026-000.
The record's own ID. Other templates point at this value.
Status*
Drives who this goes to next.
- Planned2 pts
- In progress2 pts
- Complete3 pts
- Deferred0 pts
- Open0 pts
- Closed3 pts
- Overdue0 pts
Site*
Site ID*
Format SITE-000.
Links to FDN-001 Site ID
Last Verified*
Verified By*
Next Review Due*
Know Where Every Drain Goes
In an emergency nobody has time to work out whether a gully is foul or surface water. Colour code them on the ground and map them here.
Drains
Repeats15 fieldsDrain Reference*
Location Description*
Drain Type*
- Foul, to treatment2 pts
- Surface water, to watercourse0 pts
- Unknown0 pts
Discharges To*
Site treatment, municipal sewer, interceptor then watercourse, or direct to watercourse.
- Site treatment3 pts
- Municipal sewer2 pts
- Interceptor then watercourse1 pt
- Direct to watercourse0 pts
Final Receptor
Consent Or Permit Applies*
Colour Coded On Ground*
- Yes3 pts
- Partly1 pt
- No0 pts
Marked On Site Plan*
- Yes3 pts
- No0 pts
Cover Or Grating Sound*
- Yes3 pts
- Damaged0 pts
Isolation Available*
- Yes3 pts
- No0 pts
Isolation Type
Isolation Accessible
- Yes3 pts
- Difficult1 pt
- No0 pts
Interceptor Upstream
- Yes3 pts
- No1 pt
Interceptor Reference
Links to ENV-030 Record ID
Photo
Register health
14 fieldsDrains On Register*
Unmapped Drains Found*
Drains Without Colour Coding*
Surface Water Drains In Chemical Areas*
A surface water drain beside a chemical store is a direct route to a watercourse.
Cross Connections Suspected*
- No3 pts
- Yes0 pts
Dye Testing Carried Out
- Yes3 pts
- No1 pt
Action Required*
Raise the action record, then enter its reference here.
- No2 pts
- Yes0 pts
Priority
- High0 pts
- Medium1 pt
- Low3 pts
CAPA ID
Format CAPA-2026-00000.
Links to FDN-014 CAPA ID
Action Owner
Environmental Lead*
Signature*
Site Manager*
Second Signature*
ENV-006 · record IDs look like DRN-2026-000 · Links Site
Open in KnowellaRun it with agents
From a document you fill in to a programme that runs itself
The register itself is simple to fill in. What fails is keeping it current after site changes, chasing verification of drains nobody has dye tested, and connecting a gap in the register to the spill response that depends on it.
Holds the drain register against the site's drainage as actually built, flags drains overdue for verification, and keeps the evidence trail behind each one.
Tracks which consent or permit applies to each discharging drain and flags where status is unknown or has lapsed.
Schedules colour-coding renewal and isolation-point accessibility checks so the physical drain matches what the register claims.
Cross-references spill and construction records for signals that a drain has changed, and raises the register review before the next scheduled date.
This template lives in KnowEnviro — environment and energy. Aspects, permits, waste, emissions, spills and sustainability reporting.
Meet KnowEnviro→Glossary
Drain Register definitions and key terms
- Outfall
- The point where a drainage system discharges to its final receptor, such as a sewer, an interceptor or a watercourse.
- Trade effluent consent
- Permission from a sewerage undertaker to discharge trade effluent to the public sewer, specifying what and how much may be discharged.
- Cross-connection
- A pipe run plumbed to the wrong drainage system, most often foul discharge finding its way into the surface water network or the reverse.
- Interceptor
- A device installed upstream of a drain to separate oil, fuel or silt from the flow before it reaches a sewer or watercourse.
- Foul drain
- A drain carrying wastewater to treatment, as distinct from a surface water drain, which carries rainwater with little or no treatment to a sewer, interceptor or watercourse.
FAQ
Frequently asked questions about drain register
What's the difference between a foul drain and a surface water drain?+
A foul drain carries wastewater to a treatment works built to handle contamination. A surface water drain carries rainwater, usually untreated, to a sewer, an interceptor or a watercourse. Confusing the two during a spill turns a contained event into a reportable pollution incident.
Why does colour coding matter if the register already exists?+
During an actual spill nobody has time to look up the register and cross-reference a location. Colour coding on the ground is the control that works at the speed the situation moves, and the register's job is to be right when someone eventually checks it.
What is a cross-connection and how would we know we have one?+
A pipe run connected to the wrong system, foul into surface water or the reverse, invisible from the surface. The only reliable way to know is dye testing or CCTV survey; an assumption based on the drawing is not evidence either way.
Do we need a permit or consent for every drain?+
Not every drain, but every drain discharging to a public sewer or watercourse sits under some consent or permit regime, and the register should record whether one applies and its status. Marked unknown is a gap to close, not a category to leave open.
How often should the register be verified?+
At a stated interval regardless, and immediately after any site change: new construction, resurfacing, a demolished building, or an unmapped drain found during a spill. The interval is a backstop for change nobody flagged, not the primary trigger.
What should we do if we find an unmapped drain?+
Add it immediately, establish where it discharges to before assuming, and treat its discovery as a signal to re-verify the rest of the register. One unmapped drain usually means the last verification was less thorough than it was recorded to be.
Keep going
Related templates and programmes
Industries this is written for
Programmes this belongs to
Used together in Spill and Pollution Prevention
Spill Report
Records a release of chemical, fuel, oil or wastewater
Spill Response Record
Records what was done to contain, clean up and dispose of a spill
Environmental Notification Record
Records what was reported to an environmental regulator, when and by whom
Spill Prevention Plan
Sets out how releases are prevented, including containment, storage and drainage design
Containment Inspection
Checks bunds, drip trays, drains and interceptors are intact and not full
Stormwater Outfall Inspection
Checks stormwater discharge points for sheen, colour, odour and debris
More in Spills
Spill Report
Records a release of chemical, fuel, oil or wastewater
Spill Response Record
Records what was done to contain, clean up and dispose of a spill
Environmental Notification Record
Records what was reported to an environmental regulator, when and by whom
Spill Prevention Plan
Sets out how releases are prevented, including containment, storage and drainage design
Containment Inspection
Checks bunds, drip trays, drains and interceptors are intact and not full
Written and reviewed by
Siddarth Singh
Founder & Chief Executive Officer, Knowella
Certified Safety Professional and industrial and systems engineer with more than a decade inside food supply chain, freight and manufacturing operations. This page was written against the current text of the standards it cites, not against secondary summaries of them.
- Certified Safety Professional (CSP), Board of Certified Safety Professionals
- MBA, University of Chicago Booth School of Business
- MS and BS, The Ohio State University, Industrial and Systems Engineering
- Six Sigma Black Belt
Sources and last review. Reviewed 16 August 2026 against:
- 40 CFR 122.26, NPDES stormwater discharge programme
- Water Industry Act 1991, section 118, trade effluent consents (UK)
- Environmental Permitting Regulations 2016, discharges to controlled waters (England and Wales)
- ISO 14001:2015, clause 6.1.2, environmental aspects
This page is general guidance, not legal advice. Confirm requirements with your jurisdiction’s regulator.