5 Steps for Compliant Water Management on Construction Sites

As construction managers, environmental sustainability is always at the forefront of our mind, albeit planning ways to reduce fossil fuel consumption or adapting our processes to avoid air, ground or water pollution.

One topic that is increasingly being highlighted by authorities and the media, is water pollution. In fact, water pollution has become such a hot topic, that the financial penalty for companies who pollute the environment is no-longer capped!

In December 2023, the Environment Agency were awarded new powers to issue fines that are proportionate to the size of the company and the nature of the offence - with no upper limit. Furthermore, if you are found to be responsible, you could face up to 5 years in prison.

The Environment Secretary warned that contractors who breach their permit conditions, illegally discharge water, or damage precious habitats in any way, “will pay”.

This forms part of the UK Government’s plan to ensure there is more investment, stronger regulation and tougher enforcement across the water system.

So how can you ensure you remain compliant with environmental regulations?

Rest assured. We have created a 5-step guide to help you manage water effectively and avoid fines from the Environment Agency.

Step 1: Understand your construction site.

It’s a good idea to start with a ground investigation report. You may think that you know your site, but do you have all the information you need to create a fully compliant water management plan? For example, a ground investigation report might reveal:

• Historical land use and previous contamination
• Water courses, groundwater, high water tables and perched water
• Ground conditions, topography, and existing drainage systems
• Areas liable to flooding (flood zones)
• Sites of Special Scientific Interest (SSSI) and Special Areas of Conservation (SAC)

Step 2: Understand the regulatory requirements for water treatment & discharge.  

It is usual for sites to have excess water that needs to be discharged, but as per the Environmental Permitting Regulations (2010) and the Water Resources Act (1991), it is an offence to discharge water without prior approval from regulators such as the Environment Agency (England and Wales) and Scottish Environment Protection Agency (Scotland).

Whilst it is safe to assume that you will need an environmental permit for discharging water, there are some exceptions, therefore The Environment Agency have produced a document titled ‘Temporary Dewatering from Excavations to Surface Water’ which outlines exactly when you do not require a water discharge permit.

Prior to application, it is important to identify and consult with the relevant authoritative bodies that may have direct say in your environmental arrangements (EA / SEPA / Water board / Local Council), otherwise your application may be rejected.

Also, be aware, applications usually take several months to be approved, so it is worth assessing your requirements early and submitting an application form as soon as possible. Please note, you will also be expected to have an Environmental Management System (EMS) in place.

See the Government’s Pollution Prevention for Business guidance notes for more information.

Step 3 & 4: Identify site activities, and Assess the risk of contaminants/ pollutants.

The identification of environmental risks will form part of your Environmental Management System (EMS). Here are some typical site activities you might need to consider:

• Excavations: The combination of groundworks and rainwater will result in the build-up of silt-laden puddles of water. This water can increase the risk of flooding, and would also harm aquatic life if it entered a watercourse.
• Concrete works: Water that has been in contact with cement-based products will be highly alkaline, and if this enters a watercourse, it can harm aquatic life.
• Stockpiles: For example, Limestone and recycled aggregates such as crushed concrete could affect the pH of the run-off. Water that is either too acidic or too alkaline will need to be treated before it is discharged.
• Washing vehicles & tools: Machinery that is covered in mud, oils and cement etc. will contaminate the wash water, and this cannot be discharged until it has been treated.
• Using chemicals & fuels: Many chemicals used during construction are harmful to plants and animals. It is therefore imperative to follow the COSHH regulations  and ensure that bunding and absorption materials are used to prevent leakage into water.
• Managing surface water runoff: Ground destabilisation, caused by stripping top soil and other construction works, can lead to nearby watercourses being contaminated with silt, clay and other solids. When assessing how to reduce this risk, it is important to implement a hierarchy of control (erosion controls, sedimentation controls and active controls).

Step 5: Create an action plan for managing the contaminated water.

The systems you put in place to reduce the risk of water pollution, will also need to be detailed in your Environmental Management System (EMS). Depending on the volume of water on site, you may need temporary drainage systems, pumps for dewatering, and temporary water holding areas. You then need to consider how you are going to remove silt, suspended solids, oil, hydrocarbons, and treat pH imbalance.

For example, if you are holding a large volume of water that has been contaminated with suspended solids and has a pH imbalance, you could:

• Pump the water into an EnviroHub® Treatment Tank where it is pH neutralised,
• Pass the water into an EnviroHub® Lamella Settlement Tank where the solids and liquids are separated,
• Then discharge the water in-line with your environmental permit.

RVT also offer in-stream water monitors so that you can check the turbidity, temperature and pH of any water that is discharged to surface watercourses (Eg, into a stream). This will not only give the site team peace of mind, but the data can also be used as evidence of compliance should any questions arise from environmental authorities.

As mentioned earlier, environmental permits for discharging water can take a long time to be granted, therefore you might want to consider discharging treated water to a sewer under a trade effluent license, rather than discharging it into a surface water course.

This is just one example of how an EnviroHub® system can be used to manage contaminated water on site. RVT also offer an EnviroHub® Concrete Washout System which enables silt to be removed through a geotextile bag, before reducing the alkalinity in a treatment tank.

Step 6: (Bonus step!) Speak to an RVT Consultant

No matter what challenges you are facing in relation to water management, our consultants will be able to help. They will talk you through your different options and present a fully compliant water treatment system for your site.

Plus, don’t worry if you are using unusual substances or processes, we have a team of scientists who can test different ratios of coagulant and flocculant to determine the best treatment solution for your activities!

Contact an RVT Water Consultant

RVT also offer a wide range of free resources.

Water Treatment Solutions: Why you might need a concrete washout on site

Finally, click here to view the full range of EnviroHub® Water Treatment Units.