Ground-water Levels, Flow, and Specific Conductance in Unconsolidated Aquifers Near Lake Erie, Cleveland to Conneaut, Ohio, September 1984

Abstract

This report described ground-water levels, flow, and specific conductance in aquifer along the southern shore of Lake Erie from Cleveland to Conneaut, Ohio. The data were collected in September 1984 as part of the U.S Geological Survey's Northeast Glacial Buried Valley Regional Aquifer-System Analysis. The study area is about 60 miles long, extends inland from the lake about 10 miles, and encompasses parts of Cuyahoga, Lake, and Ashtabula Counties. Water levels were measured in 202 existing wells, all of which were completed in the glacial deposits or at the contact with the underlying shale. Specific conductance was measured in 59 of the wells. Results o the survey are presented in table and map form. Unconsolidated material throughout the area consists primarily of till, whereas the bedrock consists of Devonian shale. The till is composed chiefly o silt and clay with some sand and gravel, and is less than 50 feet thick in most areas. Some valleys are filled with as much as 200 feet of glacial till and outwash deposits that are mainly sand and gravel. Ground-water levels in much of the area within 20 feet of the land surface. Contours of ground-water levels resemble a subdued version of those of the land surface, which indicates that ground water generally flows from high areas to low areas following the land-surface gradient. Locally, ground water discharges into streams. Regionally, flow is towards the north-northeast, to Lake Erie. Specific conductance ranged from 160 to 2,900 ?S/cm (microsiemens per centimeter at 25 degrees Celsius) with a median of 540 ?S/cm. Ground water with a specific conductance greater than 650 ?S/cm is localized, with no specific spatial pattern; possible sources of elevated specific conductance are road-deicing salt, leachate from landfills, natural brings associated with oil and gas drilling, and the leakage of saline water from bedrock.