23-1 Noise

Regarding the water plan, will the newly proposed water treatment system add any mechanical equipment to the site that could produce noise, such as might be associated with a zero liquid discharge system (crystallizer pumps, vapor compressors or brine rec

There is no new equipment that will produce noise that changes the results of the noise model or report that was previously submitted.

Under the water plan that was previously submitted, and that which was modeled acoustically, all noise-producing water treatment equipment, such as pumps and the reverse osmosis system, were contained inside the Water Treatment Building. In the acoustic model of the Clear River Energy Center (CREC or Facility), a noise level of 85 dBA was assumed inside this building based on measurements at other sites. The building was modeled assuming standard steel construction with ventilation openings. Resulting noise levels at the nearest residences due to this source only were more than 20 dBA below the total and, therefore, not a contributing factor at all. The revised water supply plan (Water Supply Plan or Plan) involves a smaller Water Treatment Building, due primarily to the elimination of the reverse osmosis and electrodeionization system. The new Plan adds portable demineralization trailers, which house only tanks and pipes but not pumps. The only noise source inside the trailers is flowing water. If one assumes a conservatively high noise level of 80 dBA inside these trailers, as well as the sound transmission loss of a standard 'semi-trailer', the resulting noise levels at the nearest residences are again more than 20 dBA less than the total and, therefore, non-contributing. In summary, the revised water treatment system will produce less noise than the previous system and is not a contributing factor to overall noise levels at nearby residences.