DELCORA is planning to build a tunnel from Darby Township to Chester and someone wanted me to write about it. 

What going on?

When the county created DELCORA in 1971, they built up the old wastewater plant that used to just serve Chester City and converted it to handle wastewater from the western section of Delaware County. Wastewater from the eastern section of Delaware County started going to Philadelphia in 1974. 

It’s the wastewater that’s currently going to Philly that’s causing all the fuss because the EPA is requiring Philadelphia to make some very expensive improvements to their wastewater treatment infrastructure and DELCORA must help pay for it if they want to keep sending wastewater to Philly. 

DELCORA considered three alternatives to paying an extra $880 million to Philly.  Alternative 1 is to build a new wastewater treatment plant in eastern Delco at a cost of about $613 million. Alternative 2 is dig up the streets and build a new pipeline to bring the wastewater currently going to Philly to Chester at a cost of about $560 million. Instead of using pipe, Alternative 3 is digging a tunnel to bring eastern wastewater to Chester for about $472 million. 

Pros and Cons 

The easiest thing to do is to do nothing and keep sending wastewater to Philly. Obviously, all alternatives have a huge price tag and it will result in folks having to endure rate increases for years to pay for all this. Clearly, rate increases would be twice as high with the Philly option since $880 million is about twice $472 million. I don’t think anyone wants to pay twice as much for anything if they don’t have to, especially their DELCORA bill.

Building a new wastewater treatment plant sounds like a good idea, but it’ll cost the rate payers about 50% more in rates than the tunnel project. And, it would be really difficult, if not impossible, to get a Department of Environmental Protection permit to operate a new plant. 

Laying a new pipeline across the county to bring eastern wastewater to Chester would drive folks crazy with the construction disruptions and your bill would still be higher than the tunnel option.

A tunnel is not only the least expensive alternative to bring eastern Delco wastewater to Chester, it provides two huge benefit that a pipeline can’t deliver: 1) a 95% reduction of wastewater going into creeks and the river during heavy rains, and 2) no need to lay more pipe in the event of new customers coming online in the future. 

How the tunnel works

Imagine a robot chewing a hole 100 feet underground for about 9 miles that’s about 15 feet wide. Nobody is going to see or feel the robot. Compare that to what has to happen if they’re digging up the street to lay 9 miles of pipe. 

Because the tunnel is so wide (15ft), it will never fill up with wastewater. The tunnel actually becomes a 9-mile holding tank that will trickle in a little water at a time to the Chester plant. During heavy rains, instead of what happens now where stormwater and wastewater gets dumped into the creeks and river, 95% of this combination water avoids the creeks and river and heads to DELCORA. 

What makes the tunnel such a clever solution is how little of the eastern Delco wastewater will dump into the Chester plant at one time since so much water will be held in the huge tunnel. This prevents DELCORA from having to do the difficult task of going to the Department of Environmental Protection to ask for permission to increase their permit. DELCORA will continue to operate within its current permit limit proving that they won’t be processing much more water than they currently process on an ongoing basis. 

Back in the old days, Sunoco and the current Monroe refinery along with Kimberly Clark were sending a lot more water to DELCORA for processing than what eastern Delco is going to deliver. Another benefit of the tunnel for Chester residents is how it will greatly reduce the number of trucks coming to Chester delivering wastewater. 

Environmental activist don’t like that DELCORA incinerates solids. That’s one aspect of the operation that won’t change. But, for the record, DELCORA’s contribution to total air emissions along Rt 291 from Marcus Hook to the airport represents just 0.5% of the combined total of emissions from all the industries located there. 

This is a quick and simple explanation of the DELCORA tunnel project. It’s the alternative they selected that saves rate payers money over the other alternatives, greatly reduces raw sewage going into creeks and the river during heavy rain events by 95%, and reduces truck traffic that currently bring nasty smelly wastewater to Chester that contributes to the odor issues many of us complain about. 

There’s a lot more information here: https://www.delcora.org/tunnel-project/