Heavy rains and sewage add up to health risk

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When it rains, or when snow melts, that water has to go somewhere. In New York City, a lot of that water goes down the drain. The storm water and runoff mixes in with household sewage, and it all goes off to a plant to get treated.

But when it rains a lot, the treatment plant can’t take the added volume. So all that extra water — raw, untreated sewage included — runs straight into the river. It’s called “combined sewage overflow” (CSO), and every year, an estimated 25 to 30 billion gallons of raw sewage pours into the rivers around New York City.

The northwest Bronx is home to more than 10 CSOs, including one of the largest discharge points in the city — the outflow for the Broadway sewer, which runs under Broadway and discharges into the Harlem River. It is designated as a “Tier 1” CSO, meaning it accounts for 50 percent of total CSO volume for the area covered by Ward’s Island water treatment center. It also has the most CSO incidents of any outflow in the city.

“CSOs are a major health issue. People are canoeing and kayaking in the Harlem River, and our community is polluting the Harlem River,” said Christina Taylor, executive director of Friends of Van Cortlandt Park.

The reason this particular CSO is the among the worst dates back centuries, to when the Van Cortlandts lived in what is now Van Cortlandt Park. The family dammed Tibbetts Brook, which used to run south from Yonkers all the way to the Harlem River, and created today’s Van Cortlandt Lake, Ms. Taylor explained. At some point — history is fuzzy on this, she says the best guess is a railroad company — forced Tibbetts Brook underground, into the sewer system. Park visitors can see this in action, at the waterfall by the golf house.

Expensive to treat

These days, that means even during dry weather, an average of 1.45 million gallons of water leaves Van Cortlandt Lake each day and goes into the Broadway sewer, mixes with the sewage and goes to Ward’s Island treatment plant. The water that used to be Tibbetts Brook costs the city more than $2 million a year to treat.

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NWheeler

I've seen photos of the tunnel Tibetts Brook flows in (see here, for example: http://environment.nationalgeographic.com/environment/photos/underground-rivers#/environment-underground-rivers-nyc-tibbetts_46403_600x450.jpg) but did not realize that it was connected to the City's sanitary sewer system. That's bad planning.

I like the idea of running it along the CSX right-of-way.

Great article.

Thursday, September 24, 2015
Tieger plumbing

What NYC could / should have done was having a separate storm line instead of a combination sewer system which many cities have. Leave the existing combination system in for sanitary and install a storm system along side it or Increase the new system for sanitary and use the existing piping for storm

They had options but they lacked the funding and foresight

In 1968 we had discussed this with the powers that be regarding newer buildings to install a separate storm and sanitary system in homes and offices, but as soon as these independent systems were outside of the building foundation they were twined in and entered the city combination sewers.

A proposal was suggested all storm water enter either the majestic Hudson and east rivers from an independent storm sewer system and this would be saving the water treatments plants from treating billions of gallons of clean storm water.

The DEP stated all water, even rain had to be treated before entering the rivers.

Larger building were denied a tax break (incentive ) if they installed a system of using gray water and storm water retention for lawns and other non potable usage.

With new construction booming in our area and the connecting into existing undersized systems and undersized water mains we need upgrades in sizing even with the mandatory use of low flow fixtures it still over loads the systems in place.

Another problem is because all the housing built and has its piping sized by fixture (DFU) units (7.48 gallons) which is no longer the ideal way to size piping as we are not getting the proper scouring action to prevent bacteria growth on the inner walls of sewer and drainage lines especialy in smaller systems such as 1-3 family homes and now these systems are breeding grounds for West Nile carrying mosquitos

What may be a cheaper solution is having large retention tanks installed to offer controlled flow of storm water as we have been doing for several years on new construction sites but the older buildings along Broad way do not have them and these systems are being over loaded and cause backwash into some of the apartment houses..

Many years ago I was called to clean (water jet) and do a video inspection of the sewer system behind CSAR and do a calculation how many more GPD the system could adequately handle

This is a brick type sewer in very good shape for its age and it does pass under the Henry Hudson parkway and to replace this would be a large undertaking .

By diverting storm water to a separate system will give a much longer life span to the existing systems.

By controlling the flow and infiltration of ground water entering the sewers the treatment plants would be able to handle the volume of sewerage and waste entering the system.

Also many homes have disconnected their outside leader lines (NYC plumbing code violation) allowing storm water to flow across other peoples properly or down ally ways causing a real hazard in the colder months and this run off adds more volume to the already over loaded system.

Another ideal option is taking water from the east river and or Hudson or and using it for fire fighting instead of using potable water which is going sky high in costs and availability is a serious problem facing many places in this nation.

Options are available as Mayor Rudy did an outstanding job in cutting the amount of water wasted in NYC in spite of those who fought him every step of the way

Thursday, September 24, 2015
Tieger plumbing

Update

A federal court has approved a settlement in which the Environmental Protection Agency (EPA) will update its national regulations for storm water runoff, one of the nation’s largest sources of water pollution, by November 2016.

The EPA agreed to the deadline after the Natural Resources Defense Council and the Environmental Defense Center filed a lawsuit last year to force the agency to act, more than a decade after a federal court had first ordered the EPA to do so.

The settlement does not address the substance of regulations but sets timelines for the EPA to take action on two types of storm water pollution that pose a significant threat to public health, fish and wildlife, and recreation:

Urban runoff

"Urban runoff” is the dirty water that runs off roads, parking lots and other hard surfaces in cities and suburbs after rainstorms and snowmelt, carrying toxic metals, pesticides, excess nutrients and harmful bacteria into waters nationwide. It causes beach closings around the country every year, and fouls tens of thousands of miles of streams and hundreds of thousands of acres of lakes, ponds and reservoirs.

The court order requires the EPA to update its storm water permitting rules with a proposed rule by Dec. 17, 2015, and a final rule by Nov. 17, 2016.

Back to over loading the treatment plants

Thursday, September 24, 2015