A requirement for effluent testing is typically driven either by an ongoing Environment Agency requirement that has been placed upon a site for ongoing monitoring, or a one-off assessment due to a change / potential change in cicrumstances surrounding the effluent at a site as part of determining the design criteria for a project.
Our MPC team has extensive epxerience in both taking samples in the required fashion either on an ad-hoc basis or as part of a scheduled process, as well as working with the various laboratories around the UK that are approved to process the effluent samples correctly.
Effluent sampling will include testing for the following:
• BOD - Biochemical Oxygen Demand. This test will measure the amount of oxygen in mg/litres required by the micro-organisms in the sewage to break down the matter. In the UK sewage treatment processes must reduce the BOD levels to a maximum of 20mg/L with some environmental sensitive areas requiring a lower BOD level.
• Suspended Solids (SS) are tiny particles which float in the liquid and are levels are reduced by treatment processes including settlement, biological and aeration. In the UK sewage treatment processes must reduce the SS levels to a maximum of 30mg/L for discharge to a watercourse.
• Ammoniacal Nitrogen is the nitrogen found in urine which if discharged untreated into the watercourse would have adverse effects on the ecology. Sewage treatment plants are designed to microbially facilitate the removal of nitrogen reducing the levels of nitrate and increasing the levels of oxygen which ultimately produces a harmless Nitrogen gas which is safely emitted into the atmosphere. In the UK sewage treatment processes must reduce the Ammoniacal Nitrogen levels to 20mg/L.
Proper effluent sampling is an important part of ensuring that your packaged sewage treatment equipment is compliant and working to the appropriate peformance levels, as well as understanding the type of effluent that the sewage treatment equipment is processing in the first place.
All modern packaged sewage treatment plant that is available in the UK must have passed the European Union minimum requirements in an experimental test environment however as no two sites are the same, ensuring that your installation is compliant is just as important. Test certification for packaged sewage treatment equipment is available to view on the British Water website, maintained as an approved organisation on behalf of the Environment Agency