Apr 4, 2019 | Letter presented to the Copake Planning Board - Hydrogeologist, Paul Rubin of HydroQuest
Video recording of Paul Rubin’s presentation can be found here: https://youtu.be/WlL5dX2TeyE
414 East Kerey Corners Road
Tivoli, NY 12583
Hon. Robert Haight, Chairman Town of Copake Planning Board 230 Mt. View Road
Copake, New York 12516
RE: GRJH Craryville Store – Gas Station Proposal
Dear Mr. Haight and Members of the Planning Board:
This letter is provided to supply additional technical detail and concerns to those raised in my letter of March 25, 2019. As you are aware, when reviewing development projects that may potentially have an adverse environmental impact, it is very important to review both site-specific project details and potential offsite impacts. Projects should not be considered in isolation, and review must extend beyond the four corners of the project parcels (e.g., 1.6 acres) to prevent damage to public health and the environment.
Reference to the attached and updated Figure 1 provides important environmental context relative to the proposed GRJH Craryville Store. I have added a number of key features to the GIS map. They include: 1) stream and drainage pathways that were not on the USGS map of the area (mapped using high resolution photo imagery and 2-foot elevation contours), 2) mapped wetland areas, 3) my delineation of the watershed area tributary to the project site, and 4) the approximate location of a buried culvert that underlies the project property that conducts hillslope drainage through and beyond the subject property.
Upon careful review of the geologic and hydrologic setting that is proposed for the GRJH gas station, it is my professional opinion that the site is ill-suited for any development that would use, store, or treat large quantities of chemicals and/or waste materials. While the applicant proposes protective measures that warrant detailed engineering evaluation along the lines put forth by Bart Clark, P.E. in his letter dated February 7, 2019, it is unlikely that sufficiently protective measures can be put in place that would preclude offsite transport of miscible phase hydrocarbons and septic-related contaminants (e.g., E. coli, fecal coliform, nitrogen, other nutrients) that can lead to downgradient water quality degradation and eutrophication of wetlands.
Increased nutrient loading is a well-documented cause of algal blooms, such as that produced by blue-green alga (cyanobacteria). Water confirmed with High Toxin algal blooms may cause health effects when people and animals come in contact with the water through swimming or drinking. It is important to prevent harmful algal blooms (HABs) and related water eutrophication.
Under the town zoning code, the Planning Board may only approve the proposed site plan if it determines that it adequately protects the health and safety of the community, and in particular here downstream surface waters and downgradient groundwater. [Section 232-21J, J(12)]. Based on my geologic and hydrologic assessment of the following features of the project, I recommend that you deny the GRJH application. A concise justification for project denial includes the following factors:
The site lies directly over a high-permeability sand and gravel aquifer that should be further investigated and protected for future use and Town growth;
Sand and gravel aquifers provide important recharge areas that provide high-quality groundwater to downgradient fractured bedrock aquifers (used by local homeowners), as well as essential base flow to wetlands and creeks (e.g., Taghkanic Creek);
Miscible phase hydrocarbons and septic contaminants, including within runoff, that are not 100 percent treated will degrade the underlying aquifer. The addition of sewage to an aquatic system (e.g., wetland) can, among other adverse impacts, deoxygenate the water leading to fish kills, species mortality, and harmful algal blooms;
An ephemeral stream from a 24-acre watershed tributary to the site (Figure 1) would, when flowing, likely become degraded with site contaminants. Siting a gas station directly over a flowing stream is not prudent;
Contaminants within this stream water and within highly permeable sediments would rapidly flow a very short distance until their discharge into a large wetland (greater than 100-acres). Such conditions lend themselves to wetland eutrophication which would degrade water quality and healthy ecosystems; and
Site contaminants would jeopardize the water quality in Taghkanic Creek.
Placement of a gas station above a high permeability aquifer is not a sound land use because of the potential for groundwater contamination. However, when streamflow directly beneath the site, the presence of a large wetland immediately downgradient of the site, and the Taghkanic Creek are added to the consideration, the site’s poor suitability for use with any high chemical load activity is clear. The risk of water quality degradation to the sand and gravel aquifer, the underlying bedrock aquifer, the large downgradient wetland complex, and the Taghkanic Creek that would accompany site plan approval is unwarranted. Again, due to the multiple factors reflecting the sensitivity of the project site, I recommend that site plan approval be denied and an alternate land use be contemplated for the GRJH site.
I look forward to working with you to ensure that the Town’s valuable water resources are protected.
Paul A. Rubin