How to minimize rainywater to the wastewater treatment system

[1906]

Recent frequent heavy rain makes us very difficult to treat "rainywater and oil" passing thru the oily sewer system into wastewater treatment system because of big flow quantity when it rains. Outside of the process area has clean sewers, so it's not a big concern. But, the problem is the oily sewer inside process area which can not separate rainywater from oil. This means that mixture of rainywater and oil is going to the wastewater treatment system when it rains with big quantity and it's big burden to our refinery's pollution prevention effort. So, in order to minimize rainywater into the oily sewer system inside process area when it rains, we cover oily sewer with round rubber. But this seems not good enough to contorl inlet flowrate of wastewater treatment system below design flowrate. So, ANYBODY WHO KNOWS THE SLOUTION OF THIS PROBLEM, PLEASE COMMENT. And,If there are good experienced companys out there, please let me know.

 

[sam74]

You would need to hire a company that deals with underground inspection. They would video tape lines 6" in diameter and above to locate infiltration problems you can't see. Then you would need to replace/rehab your problem areas. A cheaper method with less accuracy that you could do yourself would be a smoke test.

 

[cvg]

your problem is I&I - Inflow and Infiltration. You are controlling inflow from the surface using the rubber.

Solution might be to separate the combined sewer so that wastewater and storm runoff are collected in separate sewers. A retention basin / tank could be used to collect the storm runoff and hold it until it can either soak into the ground, or be treated by an oil/water seperator. Other best management practices could also be used such as sandbags around your inlets to keep the storm water out, more frequent cleaning to remove the oil from the ground etc.

As mentioned by sam74, to control infiltration you may need to repair your underground piping by replacing broken pipes and sealing the joints to keep storm water out and keep the wastewater in the pipes.

 

[jmrosell]

also to help with inflow you can use storwater inflow protectors in any sanitary sewer manholes. we have used them in my area and have worked great at elimnating inflow.

 

[1906]

Currently, we want to separate stormwater on the surface of process area rather than replacing underground piping because of its big amount of investment cost.

Based on above position we have right now and jmrosell's comment, could you(=jmrosell) tell me detail shape and basic concept of "stormwater inflow protector used" in your area. Your prompt answer would be very helpful.

 

[jmrosell]

1906,

The stormwater inflow protector we use is basically a plastic dish that catches the water as it comes in and holds the majority of it until it can evaporate away. here is the link to the company we use website.

http://www.frwindustries.com/if/if.html