TRE Project manager Scott Houldin, in a commentary written for the Wiscasset Newspaper and the Times-Record, acknowledged that the plant will use significant amounts of water, but states in his last paragraph, “Hopefully, you can understand why the level of engineering analysis and negotiations required makes it too premature at this time to say exactly where, in what form, and in what combination we will attain the water.”  Nevertheless, he suggests several sources, including surface water, brackish water, and gray water obtained from the Bath Water District and the Wiscasset Water District.

While Houldin outlines clearly the options for cooling water use, which may or may not prove to be viable, he does not discuss the other massive use of water in the proposed gasification plant in his recent commentary.

In a plant of this type, there are two different needs for water.  The first is relatively benign ... it is the closed loop cooling system.  Maine Yankee was built where it was so that it could utilze a loop of water to cool down the reactor by indirect exposure.  The water from the Back River did not come into direct contact with the nuclear rods, so in the normal course of activity, it did not become contaminated.  (There were several unscheduled radioactive releases over the lifetime of the plant.) The Maine Yankee loop was an open loop ... the  water returned to the Back River.  In the case of the gasification plant, the water will not be discharged.  About 90% will be evaporated immediately as the plant cools itself and will be released as steam.  The remainder would remain in the loop, with cool water added to it.
The second need requires a high-quality water source, generally fresh water that is clean, not just treated. 

Part of the gasification process, and the scrubbing processes to clean pollutants out of the coal, air and water, require vast amounts of high-quality water.  Simply put, a chemical reaction that can occur in fresh water cannot necessarily occur if other solutes, such as salts, are present.  Since gasification is at its heart, a chemical process, the amount of fresh water that will not be able to come from poor-quality gray water (containing solutes of treated biological material and other suspended particles) or brackish water will be enormous.  The majority of the fresh water used in this process is also released as steam.

It is not yet known where this high-quality water will come from, although Houldin says that the Wiscasset Water District is probably not a potential source.  During the early Maine Yankee days, fresh water for sanitary uses, plant make-up, and fire protection was piped to the plant from a reservoir called Montsweag Dam, located on Montsweag Brook, two miles northwest of the plant.   Montsweag Dam is now under the control of Chewonki Foundation, which is working toward dismantling the dam to improve fish passage.  Montsweag Dam, also known as Maine Yankee Dam, is a concrete gravity dam, 243 feet in length. Its maximum discharge is 2806 cubic feet per second, and its capacity is 195 acre feet. Normal storage is 160 acre feet. It drains an area of 10 square miles.  The dam creates a small lake used by small boaters, fishermen, and swimmers.  It is currently not available as surface water to the proposed plant.
Potable water for the Maine Yankee was initially provided by an onsite bedrock well. The well was later found to be contaminated with manganese.

Houldin has ruled out the use of groundwater, so presumably the bedrock well will not be used.  Bath Water District has indicted that water for drinking and other domestic needs might come from BWD, but that industrial fresh water would not come from the district.

The cooling loop will be able to come from partially brackish water, but such water carries its own problems, including deterioration over time of the intake valves and fish screens.  Houldin suggests diluting the brackish water with gray water from the Bath Water District, if the use of treated wastewater is approved by the EPA.  Other options for dilution include the use of surface stream water on the former Maine Yankee site.  Which surface water sources are available for Twin River’s exclusive use are also not clear.

Brackish water would not be able to be used for either the gasification chemical process or the scrubbing process to rid the emissions of most toxic elements, such as sulfur, nitrous oxide, and acids, as well as a good percentage, although not all, of the mercury produced.

Although future hope exists for the possibility of using brackish water as part of the gasification process, it is not there yet.  In a technical report written for the University of New Mexico at Las Cruces, J.A. McNeese and D.B. Wilson discuss the option of using brackish water in a gasification plant.

“A major advance would occur in gasification development if part of the required water could be supplied from brackish water sources. The main consideration in the use of brackish water as process water is the deposition of the salts from the brackish water [in the resulting product].”

In other words, the resulting coal ash would contain high amounts of salts, specifically sodium chloride, potassium chloride, and sodium sulfate.  The study examined the leachability of these salts from the coal ash left behind by the gasification process.  The two scientists went on to say, “While not a definite deterrent to the use of brackish water in an in-situ gasification process, the leaching of these salts into ground water and subsequent deterioration of the ground water aquifer would have to be considered.”

EPA scientists have long recommended that coal ash be treated as toxic waste, according to Steve Hinchman of the Conservation Law Foundation.  “However, coal industry lobbyists eventually won the day in Congress.  Whether it is classified toxic or not by the government, the end is the same.  Coal ash is a toxic waste.”

It is more toxic to the local ecosystem when it is laden with salts which could leach into the ground water and surface water systems, eventually ending up in brackish marshes where the higher salinity causes harm to most living organisms and enables the growth of anaerobic bacteria which foul the water.

The authors went on to describe corrosion problems that would likely occur within the plant if brackish water were to be used in the cooling process, shortening its lifespan.  We have seen this kind of deterioration with the Maine Yankee cooling system, resulting in the ultimate shutting down of the plant.

According to Twin River, the Back River is not a candidate for water use in any case, so the origin of the brackish water that might be used in some operations is still a mystery, as is the origin of the fresh water that might be used.

Other options for using brackish water include desalinizing it before using it, but this process is energy-intensive.  Given the vast amounts of water necessary, the cost of desalinization may prove to be prohibitive.

Houldin cites the Newington Energy plant on the Piscataqua River, as an example of a plant currently using saline water for cooling.  But the Newington Energy plant is an open-loop system, in which water returns to the Piscataqua River after cooling the plant, so the comparison is perhaps apples and oranges. 

Incidentally, the Newington Energy plant is up for sale, having made little progress last year in paying off its massive startup loans. Con Ed said in its February annual report to the Securities and Exchange Commission that the Seacoast New Hampshire plant carried a debt load of $333 million at the end of 2005 and $300 million at the end of 2006.