Hill 78: How Much Water?

		Site Search:

Hill 78: How Much Water?

1. What Are PCBs and Why Are They Here?
2. GE Dumped Its PCBs
3. What Is Hill 78?
4. How Much Water?

Hill 78 is a hill that is created from contaminated material dredged from the Housatonic River during the PCB cleanup of that river. BEAT believes that precipitation percolates through this hill and carries PCBs and other contamination into groundwater and into the Housatonic River in concentrations that are not insignificant. What follows is our evidence and argument.

Aerial photo of Allendale School, Hill 78, and Building 71 site

This is an aerial photo showing a high-level toxic waste dump called Building 71 (arrow #1) named for a nearby GE building, a second toxic waste dump called Hill 78 (arrow #2), and the Allendale Elementary School (arrow #3).

Building 71 and Hill 78 were both constructed from contaminated material taken from the Housatonic River during GE's court-ordered cleanup of that river. There is a plastic liner under Building 71, and this liner collects precipitation and runoff so that the site requires periodic pumping. Precipitation passes through the toxic hill like water passing through coffee grounds, until it finally settles in the liner and is now called leachate. The table shows the amounts of leachate pumped from the liner of Building 71 over a period of three years according to GE's monthly reports.

Volume of Leachate Pumped From Building 71 From January 2003 Through November 2005 (gallons)
MONTH	YEAR
	2003	2004	2005
January	50,000	35,000	136,000
February	30,000	30,000	116,500
March	120,000	98,000	174,500
April	100,000	107,000	192,000
May	68,000	164,000	89,500
June	65,000	147,500	130,000
July	53,000	171,000	127,500
August	122,500	214,000	55,000
September	94,000	230,000	55,000
October	84,000	177,000	378,000
November	86,500	138,000	162,500
December	102,500	146,000

Totals	975,500	1,657,500	1,616,500

In 2003, almost a million gallons of leachate were collected from Building 71. In 2004, more than a million and a half gallons of toxic leachate were collected from Building 71. As Building 71 grew from the addition of more and more toxic material, so did the volume of toxic liquid collected from the liner. More than a million and a half gallons of toxic liquid were collected from Building 71 in the first eleven months of 2005. Hill 78 is unlined, so any liquid that passes through it cannot be collected and treated. Where does the Hill 78 water go?

While it is true that Hill 78 is covered to protect it from rainfall, it is also true that Building 71 had the same type of protection during the period represented by the above data. In addition, Hill 78 covers an area of 5.6 acres while Building 71 is scheduled to grow to a final size of only 4.4 acres before it's active life is over, and was smaller than this when the data was collected. Since Hill 78 collects water from a larger area than Building 71, it probably also collects more water. We can't say for certain, because Hill 78 has no liner, so no water is pumped or collected. Any water passing through Hill 78 can only go into the soil beneath the hill. What's beneath the hill?

Pipes Beneath Hill 78 to be Discontinued

There are two pipes that run UNDER Hill 78. One carrying stormwater and one carrying sewer water from Allendale School. These pipes were never designed to have a huge, very heavy landfill built on top of them. BEAT, a concerned engineer, and other environmental groups asked about the integrity of these pipes. We were also worried about the outside of the pipes acting as a preferential pathways for PCB contaminated water to flow along. To address our concerns the pipes were examined and so was the soil and sediment at the outflow of the stormwater pipe where it emerges from under Hill 78 - where the water then flows off of GE property, under Merrill Road, and through a pipe along Commercial Street, into the Housatonic River. The pipes' integrity was suspect. The soil and sediment showed very low levels of PCBs.

During the winter of 2007-2008, the pipes under Hill 78 will be closed off, and new pipes will be laid to go around the Hill 78. Sampling for the layout of the new sewer and storm drain lines did not detect elevated levels of PCBs.

New Wells

In October, 2007, (when EPA first mentioned it would be conducting more soil sampling on the Allendale School grounds), they also announced (pdf) that GE would be installing 4 new small wells on the Allendale School grounds to measure groundwater elevation below the school property. There appears to be very high ground water here - which means that Hill 78 is sitting in groundwater? Not a good place for an unlined landfill. Ground water moves downhill - toward the river. There are monitoring wells around Hill 78.