Michigan residents are fortunate to enjoy the beauty of the Great Lakes. This abundance of fresh water, used responsibly, also is an important asset in cooling our electric generating plants and natural gas compressor stations along the Great Lakes.
The water is pumped into the plant where it absorbs residual heat from the equipment and then is discharged back into the lake or river. The water returns to the Great Lakes basin unchanged except for being a little warmer.
We are both sensitive and proactive to the reality that pumping large quantities of water through an electric generating plant creates the potential for fish mortality. We greatly reduce the likelihood of this by using screens and barrier nets to keep fish out of the cooling water.
The discharge of warmer water back into the Great Lakes Basin also has the potential to harm some fish. The degree of impact is relatively low and depends on a number of site-specific factors and the fish species involved. In other cases, the warmer water discharge is a benefit to fish during Michigan’s colder months. It’s no accident that the warm water discharge locations of Consumers Energy’s generating plants are popular with both fish and the fishing public.
Pumping water costs money, and the company's power plants must generate and use electricity for pumping like any other business. For this reason, the plants have always tried to minimize water flow and recycle water when practical to reduce energy costs and impacts to the environment. New water conservation tools and conservation mandates have added impetus to this process and are enabling the implementation of our water management strategy.
Developing water inventories at our generating plants in 2011 will constitute the first step in our water strategy implementation. The second step will involve documenting the implementation of cost-effective, voluntary Generally Accepted Management Practices (GAMP). GAMPs were developed by the utility sector under Michigan Public Act 35 of 2006. These practices are consistent with the Great Lakes Charter Annex Compact, and the recommendations of Michigan’s Water Resources Conservation Advisory Council.
Another water resource evaluation we are undergoing is participation in a study through The Great Lakes Protection Fund that’s designed to test and improve water footprint protocols. This project will help identify the best means to translate large scale water use into the appropriate processes or tools for characterizing, assessing and optimizing water use at individual industrial facilities in the Great Lakes region. This is the first of a kind study for the utility industry. We are conducting an in-depth assessment of our water use practices to find opportunities for recycling and minimization of water usage. A final report is scheduled for December 2011. Data obtained from this project will help develop pertinent metrics used to evaluate future water resource usage.
Examples of data Consumers Energy currently tracks are found in Figures 1 and 2 below.
Figure 1 shows the total volume of water withdrawn during operation of company-owned equipment, which includes all generating plants and compressor stations.
Figure 1. Company annual water withdrawal data. Reported in millions of gallons. Note: 2010 data reflects the addition of the Zeeland Generating Facility to the Consumers Energy generating fleet.
Figure 2 shows the total volume of water actually consumed during operation of company-owned equipment, which includes generating plants and compressor stations. The rest of the water is discharged.
Figure 2. Company annual non-potable water consumption data. Reported in millions of gallons. Note: 2010 data reflects the addition of the Zeeland Generating Facility to the Consumers Energy generating fleet.
Consumers Energy also has a long history of watershed conservation on Michigan Rivers, where it operates 13 hydroelectric dams that were built early in the 20th century. Over the years, company forestry workers have planted more than 25 million trees to stabilize watersheds along the Au Sable, Manistee and Muskegon rivers that had been devastated by indiscriminate logging and fires early in the 20th century. Erosion control efforts continue today as part of the land management plans Consumers Energy implements in these watersheds.
These management plans also provide for wetlands protection and periodic wetland inventories. They ensure that wetlands are not impacted by pond level and river flow requirements from the operation of our hydroelectric plants.
Consumers Energy periodically monitors water quality in its reservoirs to ensure the water temperature remains at healthy levels for fish. At some reservoirs — where cold and oxygen-saturated water is in short supply at the end of a long, hot summer — the company has installed a special type of equipment called an upwelling system. This equipment uses compressed air to draw the colder water from the bottom of the reservoir upward, making it available to pass through the hydro plant turbines and effectively cool the project outflow temperatures slightly.
These actions have resulted in the maintenance and enhancement of high-quality, blue ribbon trout stream segments. At Croton Dam on the Muskegon River, our activities have created one of the best tail water trout fisheries in the eastern United States.
Updated December 2011