Measuring Site Water Discharge

When it comes to managing water on site, it’s unlikely that you and your team have time to digest specific details for environmental regulations that come with it.

To stay legally compliant and ensure smooth operations on your project, measuring site water discharge is essential. Doing this helps detect pollution, prevent incidents, and demonstrate responsible site management - but how do you balance your time with best practice?

You don’t need to. This article outlines best practice guidance for measuring site water discharge and takes just 10 minutes to read. As always, RVT Group have technical consultants on hand to support you every step of the way.

Understand the Legal Obligations

Know who your regulators are for surface and groundwater:

• Environment Agency (EA) – England
• Natural Resources Wales (NRW) – Wales
• SEPA – Scotland
• NIEA – Northern Ireland

And know what permit you need:

• Environmental Permit – For discharging to surface water or groundwater
• Flood Risk Activity Permit – For works near main rivers
• Trade Effluent Consent – For discharge to sewers via Water Organisations

Measure Water Flow and Quality

Monitoring equipment such as flow meters must be correctly installed and deployed to ensure the most accurate results and must assess volume, flow rate and quality during storm events, pumping or dewatering and water run off on site.

Real-time water quality parameters:

• Turbidity
• Suspended solids
• pH (especially near concrete works)
• Oil and grease
• Dissolved oxygen
• Conductivity
• Redox

Lab-analysis water quality parameters:

• Hydrocarbons
• Heavy metals
• Ammonia
• Biochemical Oxygen Demand (BOD)
• Chemical Oxygen Demand (COD)
• And more

Other monitoring options include v-notch weirs or flumes or data loggers with telemetry but can require more manual intervention and give less accurate results.

Separate and Manage Water Types

Divert clean surface water away from construction zones and collect and treat dirty water before discharge, in-line with the relevant permit.

You can speak to a water treatment expert free of charge at RVT Group, call 0808 281 3150 or complete this quick form today >

Pick Appropriate Monitoring Points

By being smart about chosen measuring points, your measurements will be more representative of the task at hand.

Effective monitoring points are:

• Representative of the final discharge
• Accessible and safe for regular inspection
• Avoidant of turbulence, dead zones or mixed flows

TOP TIP – Including upstream and downstream sampling for receiving watercourses can aid environmental and impact tracking.

Set monitoring frequency to match risk levels

• High-risk discharge = Daily or continuous monitoring
• Rainfall = May need increased checks (especially large sites or sites near sensitive receptors)
• Lower risk discharge = Weekly and monthly checks

Real-time telemetry devices can detect overflows or compliance breaches quickly, allowing site times to react accordingly.

Take a look at the specifications for RVT Group’s In-Stream monitor and see how hiring this solution could help your project as early as the next day >

Record and Report Your Measurements

Record:

• Water discharge logs including volume, date and quality metrics
• Calibration records for any monitoring equipment being used
• Incident reports if discharge breaches permit conditions

Report:

• The Environmental Agency or other relevant regulatory authority (dependent on the conditions of your permit)
• Water organisations for sewer discharge

Train Site Teams

To minimise the chance of an incident during water treatment and measuring, those on site should:

• Understand flow pathways
• Know how to operate and maintain water treatment equipment
• Be trained to measure sample discharges safely

Have a Pollution Response Plan

Managing water on a construction site, even with thorough planning and all the necessary equipment cannot guarantee an incident won’t occur.

In those instances, having a plan in place can ensure everybody reacts appropriately and takes the necessary steps to prevent serious environmental damage and minimising consequences from regulators.

A good plan will include:

• Emergency shutdown procedures
• Spill kits and containment booms
• Contact numbers for relevant regulators and water organisations that may need informing

Measuring your site water discharge can ensure your water management plans are being executed in line with your environmental permit and provide you with the evidence you need to support this.

If you have a question about general water treatment or specific measurement best practice, RVT Group are on hand to support you >