intermittent pumping - clear water

[JWShira]

My client (a municipality) plans to install filters into which street sweepers will dump their loads. The liquid will run through the filters and needs to be pumped about 300 feet across a ditch to the sanitary system. Each load will put about 1500 gallons through the filter, and it all goes through pretty fast. My first thought was an E-One system, but the volume discharged from each truck is much greater than the E-One units can hold. It will be essentially clear water, so solids handling really isn't an issue. Due to costs, I am trying to stay away from a full-scale lift station with a large wetwell, but may need to go that way. Has anyone else had a situation like this and found a good, low cost solution?

 

[jartgo]

Myers makes some package stations too. I think they even have some of the fiberglass wetwell type.

 

[bimr]

Before you get too far along in your project, it would be prudent to check the regulations for proper disposal.

In Florida for example, street sweepings are solid waste and must go to a landfill.

"Recently, the FDEP Solid Waste Division issued an opinion on their authority to regulate disposal of street sweepings and stormwater sediments. This opinion states that FDEP has the "authority to regulate the storage, disposal, or reuse of street sweepings and stormwater sediments" (FDEP August 17, 1999 memo). The opinion argues that: street sweepings and stormwater sediments are solid waste; solid waste is regulated by the FDEP; solid waste which is disposed must go to either a waste-to-energy facility or a permitted landfill (Class I or II); and no general exemptions exist for materials that are recycled. The opinion indicates that while street sweepings and stormwater sediments are not generally approved for disposal in Class III landfills, they may be approved on a case by case basis."

http://www.florida-stormwater.org/pdfs/pospaper_sediment.pdf.

 

[jartgo]

I agree with bimr, I thought about that but the phone rang before I typed it in my earlier post. Your local regulators may not allow you to put stormwater into the sanitary system. In my area, it's not against the law, but it's heavily discouraged.

There are several issues with this. The most common is the capacity of the WWTP, most folks treat that like gold and wouldn't dream of using it for stormwater. Depending on the processes at the plant, too much "clean" water may cause it to be inefficient.

Having said that, if you do pursue this, you'll likely need a sanitary sewer collection system permit from the local regulators authorizing you to introduce additional flow to the collection system. They will likely want to know the nature of the flow, and at least raise an eyebrow when you tell them it's stormwater. You'll also likely need a flow acceptance letter from the WWTP owner, giving you that capacity out of their plant. When the owner of the WWTP wants to expand the plant, he likely won't be able to without first showing that he's reasonably addressed inflow and infiltration issues, which is certainly counter to the idea of sending stormwater to the plant via pumps.

At some point, I think the "tide" will change and we'll start sending runoff (from impervious surfaces at least) to the wastewater treatment plant, but right now that's generally a no no, at least in my neck of the woods.

 

[dicksewerrat]

It may looki like clean water, but unless you are using some carbon filters, it isn't. It is loaded with disolved minerals, oil heavy metals, etc. Sort of on the order of 'first flush' in storm drains. The sanitary is where it belongs.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com