In England discharges to a surface watercourse requires permission under the Environmental Permitting Regulations.
This article provides the construction industry with background on the permitting structure and assistance on the key aspects needed to complete a bespoke permit application for discharging water off-site.
When is permission needed?
Permission is required from the Environment Agency (EA) for the temporary discharge of surface water into any watercourse- for example, discharging rainfall-induced overland run-off from a construction site.
The permanent design agreements for headwalls, drainage assets, and a defined final flow rate from the site, acquired via the Lead Flood Authority (LFA) or Local Authority (LA) apply to the operational phase of the development, leading to the routine discharge of clean uncontaminated water and do not constitute permission to discharge to a watercourse during the temporary works phase.
Permission from the LA, LFA or planning body does not relate to the temporary works position where bare ground and exposed soils require active management in order to prevent pollution, often for a period lasting several years.
Planning Approval may bring a conditional requirement to manage silt and sediment run-off, but in practice this is enforced by the Environment Agency, rather than the Local Authority.
Where a discharge is made to a Local Authority (“Ordinary”) watercourse, experience shows that permission is still required by way of an Environmental Permit, obtained from the EA as the regulatory body for “Main Rivers”. This is due to the fact that minor watercourses inevitably flow to the main rivers that the EA are responsible for.
Is my planned discharge activity exempt?
Guidance provided in the Regulatory Position Statement (RPS) for temporary dewatering from excavations to surface water states that only uncontaminated water consisting of clean rainwater or infiltrated groundwater may be released from a site for up to three consecutive months under exemption.
In summary, the discharge must:
- consist of clean water only (no silt, oils or contaminants)
- not operate for longer than 3 months
- not be formed from any roadway drainage, storage area or work areas
- not contain any flocculant or coagulant (eg. secondary treatment).
Discharging water often requires a bespoke permit
You must apply for a bespoke permit if your activity does not meet the conditions for the RPS or a Standard Rules Permit, the latter is only applicable to small sewage systems.
Therefore, a bespoke permit is required to discharge water from a construction site, even if the discharge does not directly enter a main river.
How to apply and what is needed?
Applications can be made to the Environment Agency. Note that there is a fee for making an application which should be paid before submitting your forms.
The EA can take four to ten months to approve a request for a permit so we recommend you submit your application early to avoid any delays in your works schedule.
Within the application for a bespoke permit, the EA will seek information on:
- the proposed discharge
- an assessment of the risk
- how water quality will be controlled and monitored via a management system.
Most commonly, this is achieved by presenting a Water Management Plan containing:
- An overview of temporary works
- Details covering site setting, receiving water and nature of discharge (including a non-technical summary). If contaminants are known or anticipated you must carry out a Specific Substance Assessment.
- A risk assessment
- Use the Source-Pathway-Receptor model and follow the EA’s guidance on risk assessments for your environmental permit.
- Controls & treatment
- Outline treatment processes that will be followed. They will require information on the type of treatment used including comparison against Environmental Quality Standards (EQS) where a flocculant or coagulant is used.
- Monitoring and control
- Detail how interventions will be checked and monitored, with a clear process for remedial actions.
Once a permit is issued, it will come with conditions relating to water quality. It is the duty of the permit holder to ensure that all conditions noted on a bespoke permit are adhered to.
Fees
The permitting fee is payable in advance under the EA Fees and Charges Scheme. Fee changes were made in June 2024.
Bespoke permits have an annual subsistence fee. A permit will remain in place until the EA are notified by the applicant that the permitted activity has finished, at which point the permit can be surrendered.
Charges are weighted towards volume, so care should be taken to ensure that the application accurately reflects the activity on site, particularly if water may be pumped during standard work hours only.
Process & timescales
The EA’s response period is 4 months, however, in our experience turnaround times can be much longer so make sure you leave plenty of time to submit your bespoke permit to avoid delays in your works.
Upon submission the EA will undertake a screening assessment to ensure that all mandatory information has been received, including pre-payment. Once they are satisfied they have all of the information they require to assess the permit, the application will be classed as ‘duly made’ and passed to a Permitting Officer for action.
If the EA are missing information they will notify the applicant directly. The submission cannot be classed as ‘duly made’ until any missing information is received. This will result in further delays to the permit being assessed.
What conditions might be included on my permit?
The information, criteria and conditions displayed on a permit are site specific and determined by the nature of the discharge activity and sensitivity of the receiving environment.
The EA will consult externally with a number of stakeholders and internally with their own technical specialists to ensure that an appropriate level of environmental protection is in place.
For suspended solids (typically composed of silt/soil/ sediment), the key compliance value is Total Suspended Solids (TSS). Compliance values are usually set between 25 mg/l and 100 mg/l. Once this value has been set on a bespoke permit, it is the duty of the permit holder to ensure that the threshold is not breached. This will be achieved by having a monitoring plan in place.
For a further explanation on monitoring suspended solids and the difference between turbidity monitoring and Total Suspended Solids monitoring, contact us and we will send you our guidance note on monitoring suspended solids and turbidity.
Frog Environmental are trusted water quality and silt control specialists working with contractors, regulators, and consultants within construction, utilities, marine, coastal, and public sector industries across the UK.
We have decades of experience in advising clients on surface water and silt management, and industry-leading products to help avoid risks of polluting. We also run training and CPD courses (some are free to attend).
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