Testimony of Carter H. Strickland
Commissioner, New York City Department of Environmental Protection
Committee on Environmental Conservation
The Assembly of the State of New York
October 6, 2011
The Revised Draft Environmental Impact Statement Governing Natural Gas Drilling
Good afternoon, Chairman Sweeney and Members. I am Carter Strickland, Commissioner of 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 natural gas development using the hydraulic fracturing or hydrofracking drilling technique. My remarks will focus on the impacts on the watershed and infrastructure that supplies New York City residents and visitors, and approximately one million additional New York State residents, with drinking water.
I want to acknowledge at the outset the New York State Department of Environmental Conservation’s (DEC’s) hard work on this issue and the difficult policy choices that agency has had to make with regard to hydrofracking. The draft SGEIS has raised the bar on the standards for this activity in New York State and DEC has rightly recognized that rules must also be adopted before any drilling can occur. We are looking forward to commenting on the recent rule proposals. As a general matter, DEC has also been very open and willing to meet with us to hear our concerns, and we are meeting with them in the near future to present additional studies and technical comments.
The Bloomberg Administration has taken the position that drilling should not be allowed in the watershed based on, among other things, the Final Impact Assessment Study (Assessment) commissioned by DEP. The Assessment 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, therefore, 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. We therefore welcomed the news that DEC would not allow high-volume hydraulic fracturing and horizontal drilling within the watersheds of the two large cities in the state that have Filtration Avoidance Determinations—New York and Syracuse.
That ban eliminates or reduces many of the previously identified risks to the water supply. However, some potential impacts to the water supply still exist, and DEP is particularly concerned about risks to water supply infrastructure—the reservoirs, dams, and aqueducts that store and transport drinking water.
When the draft SGEIS was released two years ago, DEP’s Assessment identified several risks to the water supply infrastructure. While we stand by the entire Assessment and our earlier comments submitted to DEC, today I will focus on three issues:
- buffer areas;
- damage from microseismic events; and
- differential pressures on the tunnels.
The draft SGEIS requires additional studies within a buffer area extending 1,000 feet from aqueducts. In that buffer area, 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 will not approve drilling near the City’s aqueducts unless the City is satisfied with a study’s results, but neither the SGEIS nor the proposed rules formalize that process.
Another significant concern is over the measurement of the setback or buffer distance. Horizontal drilling adds a new complication to traditional regulatory setbacks. An illustrative graphic is attached to my testimony. It shows that where the setback is measured from the well pad, as specified in the draft SGEIS, then horizontal drilling may occur directly beneath critical infrastructure, effectively eliminating any protective buffer. DEP has recommended and will continue to recommend that the setback be measured from the end of the nearest horizontal drill leg to the tunnel or other structure or even to the edge of the spacing unit. That measuring standard ensures that, at a minimum, the buffer distance is maintained.
Let me explain why this is a concern. Many of our aqueducts pass outside of the watershed. A well pad could be located just outside the 1,000 foot buffer proposed in the SGEIS, and yet a horizontal drill leg could extend well more than 1,000 feet towards our aqueduct. In fact, horizontal drill legs have been extended over 3,000 feet when extracting natural gas, and the constantly evolving technology is likely to result in even longer horizontal drill legs. Our reservoir dams are all at the edge of the watershed and therefore have 4,000 feet of setback protection under the SGEIS. But if a horizontal drill leg were to extend 4,000 feet past a well pad, then 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). Hydrofracking fluid can act as a lubricant along the surface of any faults—of which there are many in New York State—and the reduction in friction can result in very small earthquakes. The draft SGEIS concludes that the magnitude of microseismic events, typically less than 1 or 2 on the Richter Scale, is too small to be an issue. That may be true with respect to surface structures like houses, but the City’s 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 concrete tunnel liners. Our Assessment shows a high density of small faults in the Marcellus shale area around our infrastructure. DEP is in the process of obtaining an expert in seismology to help further analyze the extent of small faults and the risk to our infrastructure, and we will be submitting comments on this risk to DEC.
Differential Pressures on the Tunnels
Hydrofracking operations are anticipated to involve pressures in the range of 5,000 to 10,000 pounds per square inch (psi) applied to gas-bearing shale formations. DEP’s 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 will increase as more wells are drilled and hydraulically fractured. We are not aware of any track record of hydrofracking in the vicinity of deep-rock water tunnels that would provide assurances of compatibility.
The three risks to our tunnels, dams, and other infrastructure that I have discussed are of particular concern because underground infrastructure cannot be easily monitored. By the time one knows there is a problem, it may be too late to avoid serious impacts. Given these uncertainties and the known geologic fractures in the areas, DEP believes that the 1,000 foot setback proposed in the draft SGEIS is inadequate to protect the City’s water supply infrastructure. In the earlier Assessment, DEP took the conservative position that a seven-mile buffer would be sufficiently protective based on a statistical analysis of rock fracture lengths. DEP is currently hiring additional experts from one of the largest geophysical firms in the Northeast to refine that analysis and to better quantify the risk to our water supply infrastructure.
I will close by noting that DEP is in constant contact with the state regarding our concerns and is actively discussing aspects of the proposed regulations ahead of submitting formal comments on the revised draft SGEIS during the public comment period. DEC is to be commended on its willingness to listen and its efforts to ensure that drilling is done safely. For our part, DEP 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 our entire water supply system.
Thank you for the opportunity to comment. I would be glad to answer any questions.