What is a Flow and load survey

Date: 12/02/19 | In: Flow and Load Surveys

Flow and load surveys can be implemented across a number of different industries and processes but are predominantly required by companies operating in the chemical & pharmaceutical and food & drink sectors.

What is a flow and load survey?

The objective of a flow and load survey is to measure the flow of trade effluent in a particular process. At the same time, ascertain either the Chemical Oxygen Demand (COD) or Biological Oxygen Demand (BOD) load of that effluent and its potential impact on the respective sewage treatment works.

Why implement a flow and load survey?

If your company holds a consent license then you will be obligated to measure – and comply! – with all of the specific parameters stated within that license. Depending on what your factory or plant processes, these parameters could include flow, temperature, pH and COD or BOD. It is imperative that the water company that handles the trade effluent you produce understands what that trade effluent contains and the impact it is likely to have on their sewage treatment works. If your process is putting an excessive COD or BOD load on the works then this could result in potentially damaging and costly issues at the works. The data gained from implementing a flow and load survey will inform this, highlighting any potential problems before they occur, and thus help to ensure compliance.

How to implement a flow and load survey

When conducting a flow and load survey we will carry out a detailed site visit and fully understand the requirements of your trade effluent license. We will then specify and install the most appropriate flow und water quality monitoring equipment. Alongside this, in order to effectively analyse and understand COD or BOD, we will apply either time or flow proportional sampling to obtain an indication of the load in the process. We can set the sampler, or use an existing sampler if there is one already on site, to take samples at specific intervals or randomly over a certain period. These samples are then sent to a laboratory for detailed analysis. Once we have all the information to hand, we can produce a comprehensive report outlining the results of the flow and load survey.

Thinking of installing your own treatment works?

If you operate a large chemical or pharmaceutical plant, or a food or drink processing factory, you may be considering building your own treatment works to process trade effluent. In this case, we highly recommend undertaking a flow and load survey before any design or construction work begins. The survey will provide invaluable data to guide the planning process and ensure that the works has sufficient ability and capacity to cope with the effluent it will be required to process.