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Testimony of Paul Rush
Deputy Commissioner, Bureau of Water Supply
New York City Department of Environmental Protection

Committee on Environmental Protection
Council of the City of New York

September 22, 2011


Oversight - The Revised Environmental Impact Statement on Hydraulic Fracturing and the New York City Drinking Water Infrastructure


Good afternoon, Chairman Gennaro and Members. I am Paul Rush, Deputy Commissioner of Water Supply at the New York City Department of Environmental Protection (DEP). Thank you for the opportunity to testify today on the Revised Draft Supplemental Generic Environmental Impact Statement (draft SGEIS) on hydraulic fracturing and the New York City drinking water infrastructure.

Mayor Bloomberg has consistently held the position that New York City (the City) is opposed to drilling for natural gas in the City’s watershed using the technique known as horizontal drilling and high-volume hydraulic fracturing (hydrofracking). The Administration based this position on, among other things, the Final Impact Assessment Study, commissioned by DEP, which concluded that current technologies and practices used in natural gas drilling and exploration are incompatible with the operation of New York City’s unfiltered water supply system and pose unacceptable risks for the more than nine million New Yorkers in the City and State who rely on the City’s water supply system. Until the technical assessment was complete, the Administration had deferred taking a stand on the advisability of drilling, preferring instead to be guided by science and technological expertise. Then, based on that assessment, the Administration called for a prohibition on any drilling in the New York City west-of-Hudson watershed.

On July 1st, the New York State Department of Environmental Conservation (DEC) released a summary of its Revised Draft Supplemental Generic Environmental Impact Statement (draft SGEIS) and made it available on its website a week later; however, the comment period was not triggered until an additional report completing the document—a Socioeconomic Impact Analysis Report—was incorporated into the draft SGEIS, which was released on September 7, 2011. Comments are due by close of business on December 12th. At this time DEP and its consultants are reviewing the document and preparing comments.

The City welcomed the news that high-volume hydraulic fracturing and horizontal drilling would not be allowed within the water  supply watersheds of the two large cities in the state that have Filtration Avoidance Determinations —New York and Syracuse. This ban eliminates or reduces many of the previously identified risks to the water supply. However, some potential impacts to the water supply still exist—the most serious ones are related to the water supply infrastructure.

When the draft SGEIS was released two years ago, several risks to the water supply infrastructure were identified in the technical assessment. These include risks from:

  1. direct penetration of a tunnel;
  2. damage from microseismic events;
  3. differential pressures on the tunnels; and
  4. contamination from subsurface migration of fluid and/or gas.

The draft SGEIS proposes a setback of 1,000 feet from the aqueducts where drillers would need to conduct a site-specific analysis to identify whether drilling poses significant adverse environmental effects. If any potential effects are identified, the driller would need to initiate a full environmental impact study before drilling could be approved. DEC has offered assurances that it would not approve drilling unless the City is satisfied with a study’s results, but authority over whether drilling would then be allowed to proceed remains with the State. Another significant concern is how the setback or buffer distance is measured. Horizontal drilling adds a new complication to traditional regulatory setbacks. If the setback is measured from the well pad as specified in the draft SGEIS, then horizontal drilling may occur directly beneath critical infrastructure. Instead we plan to recommend that the setback be measured from the end of the nearest horizontal drill leg to the resource in question or even to the edge of the spacing unit.

The reservoir dams are all at the edge of the watershed and therefore have 4,000 feet of setback protection. But if a horizontal drill leg extends 4,000 feet and the setback is measured from the well pad instead of from the termination of the horizontal leg, hydrofracking could occur directly underneath a dam.

Microseismic events can occur either from the fracturing of the rock or from injection of fluids subsurface (underground). The hydrofracking fluid acts as a lubricant along the surface of the fault and the reduction in friction can result in very small earthquakes at depth. The draft SGEIS concludes that the magnitude of microseismic events, typically less than 1 – 2 on the Richter Scale, is too small to be an issue. This is likely true with respect to surface structures like houses but the City’s risk assessment concluded that this is not necessarily the case for the water supply tunnels. Repeated microseismic events over the course of years could have a detrimental effect on the concrete tunnel liners. DEP is in the process of obtaining an expert in seismology to help assess this risk to the infrastructure.

Hydrofracking operations are anticipated to involve pressures in the range of 5,000 - 10,000 psi. The structural analysis using tunnel specifications indicated that differential pressures as low as 20 psi could have a detrimental impact on the unreinforced concrete liners of the Delaware tunnels. These tunnels were not designed to withstand this type of subsurface activity (and indeed, the Rondout-West Branch Tunnel has already demonstrated a susceptibility to cracks under certain conditions). The risk from elevated pressures increases as more wells are drilled and hydraulically fractured (fracked).

Migration of fluids or gas was identified as a serious risk in our natural gas technical assessment. The fluids may be the salty formation water, left from the shallow sea that formed the shale, or the flowback water, essentially residual fluids from the hydrofracking process. This migration may be laterally from the well bore (e.g. well-casing failure) or vertically through pre-existing fractures in the bedrock. The probability that fluid and/or gas could migrate through inter-connected fractures increases over time as several hundred wells are drilled and fracked—every year for decades.

Unlike risks from surface events such as turbid runoff or chemical spills, the risk to the tunnels cannot be easily monitored and the situation is analogous to groundwater contamination—by the time you know there is a problem, it is already too late to avoid serious impacts. Given these identified risks to the City’s water supply infrastructure, the 1,000 foot setback proposed in the draft SGEIS is inadequate to protect the water supply. Based on the technical assessment, DEP took the conservative position that a seven-mile buffer would be sufficiently protective of the City’s water supply infrastructure. This distance was based on the length of mapped fractures and the likelihood of migration of hydrofracking fluid from wells or defective drilling casings through fissures in the geological substrate in the region. DEP is currently hiring additional geophysical expertise through our joint venture consultant to more thoroughly analyze and evaluate this issue.

The City is discussing its concerns with the state ahead of submitting formal comments on the draft SGEIS during the public comment period. We will continue to rely on science and technical expertise to inform our position on these issues of concern to protect the integrity and safety of the water supply infrastructure and the system as a whole.

Thank you for the opportunity to comment. I would be glad to answer any questions.

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