22-30 Water Supply Plan

Please provide the identity and location of all power plants Invenergy or its subsidiaries (or other operators) operate with the newly proposed water/sewer saving technology to be incorporated into the CREC plant.

Invenergy utilizes the mobile demineralizer trailers at their Cannon Falls, MN, Spindle Hill, CO and Ector County, TX facilities and has used them on a temporary basis at other facilities, such as Invenergy’s facilities in St. Clair Ontario, Nelson, Illinois and Grays Harbor, Washington State.

The water savings technologies identified under the Water Supply Plan are conventional water treatment technologies that have been employed at many power plants and industrial facilities in one form of another for many years.  In this application, the water saving technologies are not unique nor are they new.  The water saving technology that will provide the most significant benefit to the reduction in water use and wastewater reduction at CREC is the use of Ion Exchange Resins in the form of mobile demineralization trailers and some simple industrial filtration systems. 

Ion Exchange Resins have been employed for many years at many electric utility generating facilities and at many industrial facilities to produce high purity demineralized water from local water supplies.  The Ion Exchange Resins once depleted by the removal of dissolved salts in the water supply must be regenerated by use of acid and caustic solutions.  Mobile Demineralizer Trailers are simply ion exchange resin vessels and piping mounted on mobile trailers so the regeneration of the ion exchange resins can be conducted at the mobile trailer vendor’s facility where the ion exchange resins are regenerated avoiding a need to chemically regenerate the ion exchange resins at the user’s facility. 

The use of mobile demineralization trailers employing ion exchange resins significantly reduced water use and wastewater generation at the CREC facility over the previously proposed on-site water treatment system albeit at an increased cost for the trailer demineralizer service.  The mobile demineralizer trailers contain only ion exchange resins stored in demineralizer vessels and do not transport any chemicals.

To reduce water use and recycle wastewater at CREC other industrial filtration systems will also be employed.  These filtration systems are industrial size filters that in a smaller form are used by many homeowners as swimming pool filters.  Cartridge, sand and pre-coat type filters are commonly used by many home owners to filter swimming pool water to remove suspended dirt, hair and oil from swimming pool water.  These same filtration systems at an industrial size will be employed at CREC to remove particulates, dirt and potentially low levels of oil from floor and equipment drains and from boiler blowdown within the facility. The filtered water will be recycled to the Service Water Storage Tank for processing by the mobile demineralizer trailers for the removal of dissolved salts.

GE Mobile Water Inc. is one of the vendors that supplies mobile demineralizer services and attached as Exhibit 2 is a letter from GE Mobile Water that provides additional information on the breadth of their services.