Monroe County: Committee studies underground landscape
10/5/2005IDA - The study of Monroe County's underground landscape has moved northeast, but its main goal - finding exactly how water moves below the surface so that local officials can make informed development decisions - remains on the "to do" list.
Monroe County's ad-hoc "karst" committee is scheduled to meet again tomorrow to identify the next few sinkholes and other subterranean features it will study in the coming year.
Karst areas form as surface water containing carbon dioxide from the air and dead plant material seeps or is forced into the bedrock layer of the soil, causing the bedrock to saturate with water and erode. Eventually the voids in the bedrock form caves or sinkholes, affecting not only the integrity of the land above but also the quality of the groundwater below as minerals from the dissolving rock concentrate in the water.
Over the last year, the karst committee has been experimenting with a pair of sinkholes along Plum Creek between Ida West and Dunbar roads, just north of Ida, said Ned Birkey, a member of the committee and the county agricultural extension agent. At the location, a large amount of water from Plum Creek disappears below ground, and committee members wanted to see where it went.
Using a dye and volunteers from homes surrounding the area, the study group was able to determine that the water in the creek found its way into the underground aquifer and subsequently, into the wells of local homeowners.
It can be a dangerous situation, Mr. Birkey said, because "any contaminants in the surface water, like agricultural runoff, could end up in people's drinking water."
The karst group used a $3,500 grant to try and seal over the fractures in the bedrock believed to be responsible for the sinkholes. They piled on layers of fill stone, blue clay, and waterproof fabric to reinforce the streambed, only to have their efforts washed away by high water runoffs from the spring rains and snow melt, Mr. Birkey said.
The farmers near the sinkholes instead have agreed to a contract with the US Department of Agriculture to establish grass "filter strips" between the creek and their fields to absorb and contain agricultural runoff. They've also agreed not to chemically treat those areas of their fields that abut the filter strips, Mr. Birkey said.
In previous years, the committee has been studying the "Big Sink," an area located just east of US 23 near Samaria Road that is believed to be the largest sinkhole in the county.
With no way to effectively stop the sinkholes from contaminating the underground water supply, the karst group will turn this year to an effort to map known karst areas across the county to create a "karst risk" map that local officials can access.
The map will be put together using global positioning technology and identify problem areas, as well as data mined from previous geologic studies of the county that date back to 1899. Some of those early studies talked of farmers pulling "live fish with no eyes" from their open wells, indicating that their might be an underground link between Monroe County's aquifer and Lake Erie.
"We have a lot of new elected officials, and some of them are not aware of the [geology] of the county," Mr. Birkey said. The extension office is planning a tour of known karst areas in the county later this month for elected officials to learn about their dangers.
"We have to do something. We just can't sit still," Mr. Birkey said.