5. Geologic, Hydrologic, and Climatological Setting

5.1 2020 Climate Summary

Precipitation for the year was 36.81 inches, which is 99% of normal (0.49 inches below average). The average temperature in 2020 was 48.08°F, 1.48°F above normal. Additional climatological data can be found at: Northeast Regional Climate Center.

5.2 Geology and Hydrology

The CDS and RDS are underlain by approximately 10 to15 feet of glacial till and 20 to25 feet of shallow highly fractured predominantly shale bedrock that transitions to more competent bedrock at a depth of about 40 feet below ground surface. Groundwater is present in all three zones, with the fractured shale being the predominant flow zone. The general direction of groundwater flow is southwesterly in the till, southwesterly in the fractured shale bedrock, and westerly in the competent bedrock.

Surface water flows from northeast to southwest across the CDS and RDS, often following drainage pathways such as culverts and ditches. Two intermittent streams flow southwest from the vicinity of the sites and eventually combine to form the south branch of Twin Glens Creek. Twin Glens Creek flows into Cayuga Lake approximately three miles west of the sites.

5.3 Hydrogeology

Groundwater elevation data were collected approximately quarterly from till, fractured shale, and bedrock wells at both the RDS and CDS. The complete set of raw water level elevation data from 2020 is on file at Cornell and has not been included in this report.

The direction of groundwater flow in this zone is generally toward the southwest. Even though groundwater elevations in 2020 varied with the season, the direction of flow remained consistent with previous observations.