Well Drilling Requests Cause Concerns at Mackinaw City
By Paul Gingras

Requests by hotel owners to drill new wells within the borders of Mackinaw City, an area served by a municipal water system, have sparked concern by the village council about protecting the public water supply from potential contamination, problems associated with connections between wells and the village water infrastructure, and the possibility of illegal use of the public water supply.

To serve their facilities on South Huron Avenue, hotel owners Enzo Lieghio and William Mellish have requested county health department permission to drill wells for geothermal systems and irrigation systems, but they require village permission to do so.

At the Thursday, July 3, council meeting, trustees expressed interest in allowing wells for environmentally suited geothermal systems, which can be easily monitored by the village. They are more concerned about irrigation wells, which would be difficult to monitor.

Protecting the aquifer beneath the area is paramount, said Village Manager Jeff Lawson. To find out the overall impact of allowing multiple wells in the village, the council authorized Mr. Lawson to contact a downstate company called Ioniabased Peerless Midwest for expert hydrology advice.

Only a few wells exist inside the village, all drilled before Mackinaw City's water system was built. Since drilling new wells opens the door for potential problems, and the village already has a water system, there should be strong, rational reasons to drill new wells, Mr. Lawson said.

The village utilities committee met Tuesday, July 15, to consider wells for geothermal heating and cooling systems. Issues regarding irrigation wells will be dealt with separately at a later date, Mr. Lawson said.

Owing to their capacity to provide energy-efficient heating and cooling, geothermal systems appear to be a good reason to allow the drilling of new wells, Mr. Lawson said.

Utilities Committee Chairman Matthew Yoder agreed. Disallowing them would be "almost irresponsible," he said.

Wells used for irrigation systems are more likely to cause problems because the village has no way to effectively monitor them, Mr. Lawson said in response to public questions.

Wells for open-loop geothermal systems would involve drilling about 200 feet to draw water into heat exchange units above ground. Geothermal systems would allow businesses a cost-effective way to heat their facilities in the winter. In the summer, the same systems can be used for air conditioning, Mr. Lawson said.

Installing geothermal units is expensive, so the village does not anticipate many requests for new wells to serve them.

Once water is used by geothermal systems, it remains clean and can be discharged back into the ground, a drain field, or the stormsewer system. Chris Brown, who works on large hotel projects in the village, attended the July 3 meeting. He insisted wells for irrigation systems are safe, and pushed for their approval.

Mr. Lawson suggested that water used by the geothermal system could be stored for irrigation, making a separate well for irrigation unnecessary.

For geothermal systems, the village would install a meter on each well. The village would know the capacity of each system, 40 tons of cooling capacity for example, which would draw 120 gallons per minute at peak flow. If the system functioned outside its range, village workers would be alerted and would know they should investigate whether a leak or cross-connection problem had occurred, Mr. Lawson said.

In this case, cross connection means a private water system has been linked to a public water system. This could be done accidentally, especially if a future business owner were to alter the plumbing, unaware of the details of the two separate systems serving the building, Mr. Lawson explained.

Another problem would be the potential for a private well to be used for plumbing in the village. This is illegal according to the village ordinance, which requires any business within 200 feet of the municipal water system to hook to it. Further, the state requires businesses providing water to multiple users to have state-approved systems.

Water contamination is a key concern. Using a simple example,

Mr. Lawson said that someone using a hose connected to a spray bottle with chemicals to kill lawn pests can fall victim to pressure changes. During a pressure change, water can be sucked from the container with the pesticide back into the building, contaminating the water supply.

There are many documented cases of this, he said.

This can occur in large-scale irrigation systems, and if there are cross-connections between the well and the public infrastructure, contaminants could flow into the public water supply. There are few documented cases of this because large-scale irrigation using private wells within the limits of a city are seldom allowed, he said.

Unlike the wells proposed, all irrigation systems connected to municipal water infrastructure include equipment to prevent this kind of pressure-related back flow, he said.

Expert advice is needed because the more penetrations there are into the aquifer, the more potential there is for water contamination. Commonly, contamination in wells occurs when a facility is abandoned and a well is not properly sealed.

Although serious contamination problems are not likely in Mackinaw City, the municipality "should be concerned about any penetration into the aquifer," Mr. Lawson told The St. Ignace News.

Since the village ordinance is not specific enough to address wells for geothermal systems, the village is looking at the individual circumstances of businesses who request them, he added.