sewar dept concerned about spills

[mattabv]

All is going all ahead full when sewer dept request a retention tank in sewer line and containment area to keep alcohol from entering sewer system. has anyone out there experienced this and if so is there a legitimate argument with supporting research to corroborate it. I would appreciate any input from anyone who can help. Thanks

Matt

[John McKee]

Your local municipality gets to make its own rules when it comes to what it allows through the sewer and municipal treatment systems. However, here are some bullet points that you can use to support the fact that you don't need to have containment:

• Ethanol and water are infinitely miscible. Meaning, in the event of a spill you can open the hose and dilute the stream going down the sewer to a point where it will be virtually non-detectable.
  
• Your maximum possible spill is what?.....a barrel. Maybe a proofing tank. Your volume will determine the max, but as a micro figure your largest possible spill will be less than 250g. The toilets from the buildings on your block will put 4 times that down the drain every few hours. Again, combined with the argument from the first bullet, they'll never even notice the ethanol in the mix of effluent from the entire remaining contributions to the system.
  
• In spill containment regs, the rule is that you build a containment system of 1.25x of the largest possible tank in your facility. This might seem like a lot, but for a 250g tank, that's probably a berm around the tank about 4" high. You could argue that you'd be willing to put a berm around your tank farm rather than in the outlet to your sewer system.
  
• Or you could tell them you'd be willing to install a block valve in the primary sewer drain. Basically, ensure them that you could stop anything from entering the system if something was to happen.
  

Good luck. Sorry I can't be more helpful.

Cheers.