Relating Drainage Plans to Pollution Pathways

Our previous blogs provide a lot of information about drainage plans; you can read here about why you should have a drainage plan, and here about what a pollution pathway is.  This blog will discuss your drainage plan, how you can use it to determine pollution pathways and why this is useful.

What is a pollution pathway?

Based on the source, pathway, receptor model, pollution pathway describes the route pollution can or will take from where it was generated (the source) to where it ends up (the receptor).

What is a drainage plan?

This plan shows all underground site drainage and associated infrastructure like interceptors.  You can read all about what a drainage plan should include here, but it must be an accurate representation of actual site arrangements.

Drainage plans and pollution pathways

When pollution planning, it is essential for you to consider all source, pathways and receptors.  This will enable you to put appropriate controls in place to prevent pollution, and to plan what to do if pollution occurs.  A good quality and clear drainage plan is essential in this process and should show your entire site.

Beginning with your drainage plan, you can overlay your pollution risk areas.  Some are obvious like refuelling areas, fuel and chemical storage areas and vehicle washes, but don’t forget other areas such as car parks and battery charging areas that could also pose a pollution risk.  Once you have identified these sources, you can use your drainage plan to identify your pollution pathways.  Drains are obvious, but you must identify whether they are foul or surface water drains as this will inform the risk, receptor and what you should do after an incident.  Your drainage plan will also be able to tell you whether an interceptor or other pollution control devise, like a penstock valve or similar could be used to intercept the pollution and prevent it from leaving your site.  Your drainage plan will also tell you if there are any bodies of water on or near to your site like a bordering canal or stream or balancing ponds on site that may become contaminated.  You should also consider any areas of unmade ground that may become polluted in an incident and become a pathway to groundwater.

What do I do now?

Once you have identified your pollution pathways, you will be able to assess the controls you have in place to intercept pollution and whether they are sufficient.  If they are not, you can review and put additional controls in place and use this information to inform emergency plans and ensure your staff know the best way to deal with a pollution incident to protect the environment.

Your drainage plan is an essential document that will assist in many areas of operational and emergency planning.  Using it to identify your pollution pathway and take the appropriate action will help you to manage your pollution risk and reduce the likelihood of a major incident.