Statutory Inspections · Mandatory · Pre-Construction

Water Discharge Activity / Dewatering Consent Record

A record tracking Environment Agency permits or exemptions for construction dewatering discharge to watercourses or surface water drains. Covers permit/exemption status, water quality monitoring (turbidity, pH, suspended solids), treatment methods (settlement lagoons, flocculation), and sewerage undertaker consent for foul sewer discharge. Discharging without a permit is a criminal offence under EPR 2016.

Last reviewed: 2 April 2026 — This guide reflects UK law as of this date. Environmental Permitting Regulations 2016 remains current with no amendments enacted as of 2 April 2026. Next scheduled review: 2 April 2027.

Legal basis	Environmental Permitting (England and Wales) Regulations 2016 (EPR 2016)
Record type	T15 Water Discharge / Dewatering Consent Record
Requirement	Any discharge to a watercourse (river, stream, ditch, canal, lake, coastal water) needs an EA permit or registered exemption
Criminal offence	Discharging without a permit is a criminal offence under EPR 2016 — unlimited fines and up to 5 years imprisonment
Regulator	Environment Agency (EA) in England; Natural Resources Wales (NRW) in Wales
Sewer discharge	Discharge to a public sewer requires consent from the sewerage undertaker under the Water Industry Act 1991 — separate from the EA permit

1. What It Covers

A water discharge consent record tracks the regulatory approvals and monitoring required for any discharge of water from a construction site to a watercourse or groundwater. Under the Environmental Permitting Regulations 2016, any discharge to inland freshwaters, coastal waters, or groundwater requires either an environmental permit from the Environment Agency or a registered exemption. Discharging without a permit is a criminal offence carrying unlimited fines and up to five years' imprisonment. The EA prosecutes construction site discharge offences regularly, and ignorance of the requirement is not a defence.

The most common construction site discharge scenario is dewatering — pumping groundwater or accumulated surface water from excavations, basements, or trenches and discharging it to a nearby watercourse or ditch. Even clean groundwater can cause environmental harm if it carries silt, cement wash, fuel, or other contaminants into a watercourse. The discharge consent record should track the permit or exemption status, the receiving watercourse details, the treatment methods applied before discharge, the water quality monitoring regime and results, and any incidents or breaches. Where the discharge is to a public sewer rather than a watercourse, consent from the sewerage undertaker is required separately under the Water Industry Act 1991.

Even apparently clean groundwater can cause environmental harm

Groundwater pumped from excavations may appear clean but can carry elevated levels of suspended solids, iron, manganese, or other naturally occurring substances that cause environmental harm when discharged to a watercourse. Silt-laden water smothers aquatic habitats, changes the pH of the receiving water, and can be visually obvious to EA enforcement officers. The discharge must be treated (typically by settlement, filtration, or pH correction) before it enters the watercourse, and the treatment method must be specified in the permit application and maintained throughout the dewatering operation.

“A person must not...cause or knowingly permit a water discharge activity...except under and to the extent authorised by an environmental permit.”— Environmental Permitting Regulations 2016 Regulation 12(1)(b)

2. Key Content

The water discharge consent record should track every aspect of the discharge authorisation, monitoring, and compliance. The following table sets out the key areas to be recorded.

Area	Detail required
Project reference	Development name, site address, planning application reference, principal contractor name and contact, environmental manager or responsible person
Receiving watercourse	Name and classification of the receiving watercourse (river, stream, ditch, canal, lake), Water Framework Directive status, grid reference of the discharge point, distance from the site to the discharge point, sensitivity of the receiving water (presence of protected species, proximity to abstraction points, designated sites)
Dewatering activity	Description of the dewatering activity — source of water (groundwater, surface water, or both), estimated pumping rate (litres per second), estimated duration of dewatering, number and location of pumps, discharge route from pumps to the watercourse
Site condition	Ground conditions from the site investigation — groundwater level, soil type, contaminated land status, presence of hydrocarbons or other contaminants in the groundwater, baseline water quality data for the receiving watercourse
Permit / exemption	EA environmental permit reference number and date of issue, or registered exemption reference. Permit conditions including discharge limits (suspended solids, pH, hydrocarbons, metals), maximum discharge rate, monitoring requirements, reporting obligations. Date of permit application, date of determination, any pre-application advice received
Sewerage undertaker consent	Where discharge is to a public sewer rather than a watercourse: sewerage undertaker consent reference, conditions of consent (flow rate limits, quality limits, duration), consent fee, trade effluent consent if applicable. Name of the sewerage undertaker and contact details
Treatment method	Treatment system for the discharged water — settlement tanks or lagoons, silt fencing, lamella clarifiers, pH correction dosing, oil interceptors, activated carbon filters. Treatment system capacity relative to the pumping rate, maintenance regime for treatment equipment, contingency arrangements for treatment system failure
Monitoring frequency	Frequency of water quality monitoring as required by the permit conditions — typically daily visual inspection, weekly sampling for suspended solids and pH, and event-based sampling after heavy rainfall or operational changes. Monitoring schedule and responsible person
Results log	Log of all water quality monitoring results including date, time, sample location (upstream, discharge point, downstream), parameters measured (suspended solids, pH, dissolved oxygen, hydrocarbons, temperature), results, compliance with permit limits, and any exceedances
Incidents	Record of any discharge incidents including date, time, nature of the incident (silt discharge, pH exceedance, oil spill, treatment system failure), immediate actions taken, EA notification details (date, time, EA officer name, reference number), investigation findings, corrective and preventive actions
Contact	EA local office contact details, EA incident hotline (0800 80 70 60), sewerage undertaker contact details, environmental consultant contact details, site environmental manager contact details

3. Common Mistakes

Assuming small-scale dewatering to a ditch does not need EA permission

There is no de minimis threshold for water discharge activity under EPR 2016. Any discharge to a watercourse — including a ditch, field drain, or land drain that connects to a watercourse — requires either an environmental permit or a registered exemption, regardless of the volume. Pumping a few hundred litres of silty water from a trench into a roadside ditch is a water discharge activity and, if done without a permit, is a criminal offence. The EA has prosecuted construction companies for exactly this scenario. The only exception is where the discharge qualifies for a registered exemption, but even an exemption must be formally registered with the EA before the discharge begins.

Discharging without adequate treatment

A permit authorises a discharge subject to conditions — typically limits on suspended solids concentration, pH range, and hydrocarbon content. Discharging untreated water that breaches these limits is a breach of the permit conditions and can lead to enforcement action, including prosecution. The treatment system must be designed to handle the expected pumping rate and the contaminant load, must be maintained throughout the dewatering operation, and must have contingency arrangements for equipment failure. Simply pumping directly from the excavation to the watercourse without settlement or filtration will almost certainly breach the permit conditions.

Not monitoring the receiving watercourse upstream and downstream

Permit conditions typically require monitoring of the receiving watercourse at points upstream and downstream of the discharge point to demonstrate that the discharge is not causing environmental harm. Failing to carry out this monitoring — or failing to keep records — is a permit breach in its own right and also means the contractor cannot demonstrate compliance if challenged by the EA. Monitoring should begin before dewatering starts (to establish baseline conditions) and continue throughout the dewatering operation and for a defined period after it ceases.

Confusing EA discharge permit with sewerage undertaker consent

An EA environmental permit authorises discharge to a watercourse (river, stream, ditch, coastal water). Consent from the sewerage undertaker authorises discharge to the public sewer system. These are entirely separate authorisations from different bodies. Discharging to a watercourse with only a sewer consent, or discharging to a sewer with only an EA permit, is not compliant. The discharge consent record must clearly identify the receiving destination and confirm that the correct authorisation is in place for that destination.

4. Frequently Asked Questions

What happens if I discharge without a permit?▾

Discharging to a watercourse without an environmental permit (or registered exemption) is a criminal offence under the Environmental Permitting Regulations 2016. The offence carries unlimited fines on conviction and up to five years' imprisonment. The Environment Agency actively investigates construction site discharges and has a strong track record of prosecution. In addition to criminal penalties, the EA can issue enforcement notices requiring immediate cessation of the discharge and remediation of any environmental damage, and can recover its investigation and clean-up costs from the offender. The reputational damage to a construction company following an EA prosecution can also affect future tender opportunities and client relationships.

How long does it take to obtain an EA discharge permit?▾

The EA's published determination period for a standard water discharge permit is up to four months from the date of a duly-made application. However, processing times can vary depending on the complexity of the discharge, the sensitivity of the receiving watercourse, and the EA's workload. Pre-application advice from the EA is recommended and can help to identify issues that might delay the determination. For straightforward construction dewatering discharges, the EA may also offer a regulatory position statement or general binding rules that provide a faster route to authorisation, subject to meeting specific conditions.

Can I discharge dewatering water to a soakaway instead of a watercourse?▾

Discharging to a soakaway constitutes a groundwater discharge activity under EPR 2016, which also requires an environmental permit or registered exemption. Groundwater discharge permits are generally more difficult to obtain than surface water discharge permits because of the risk of contaminating the aquifer. If the groundwater being pumped is clean and is being returned to the same aquifer via a soakaway, a registered exemption may be available. However, if the water has been contaminated (for example, by contact with cement, fuel, or contaminated soil), an environmental permit will be required for the groundwater discharge.

What monitoring parameters should I test for?▾

The monitoring parameters will be specified in the environmental permit conditions. For a typical construction dewatering discharge, the EA commonly requires monitoring of: suspended solids (the most common cause of permit breach on construction sites), pH (cement contact can raise pH to harmful levels), dissolved oxygen, temperature, visual assessment (colour, turbidity, oil sheen), and hydrocarbons (where there is a risk of fuel or oil contamination). For sites with contaminated land, additional parameters such as heavy metals, PAHs, or specific contaminants identified in the site investigation may be required. Monitoring must be carried out at the frequency specified in the permit and results must be recorded and retained for inspection.

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