SITE INFORMATION AND CORRESPONDENCE

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5.14 WASTE MANAGEMENT • Scattered surface deposits and push piles of gray silty material with waste materials characteristic of wastewater pond sludge were observed in the northern portion of the site (likely remaining from the temporary stockpiling of sediment in the 1980s and 1990s). Laboratory analysis of samples is recommended to assess if the silt contains elevated levels of any metals of potential concern,and if any special handling, disposal, or placement requirements would apply to the materials during project development. Alternatively,the materials could be removed from the site to an appropriate disposal facility, and confirmation samples of the underlying material could be collected and analyzed to verify adequate removal has taken place. • Suspect oil staining was observed on the ground surface near the gravel road on site. It is recommended that the extent of the affected area be observed by an environmental professional during project development to determine if extensive oil staining is suspected and if soil sampling and analysis is warranted. • There is no intent to use the shallow/perched zone groundwater at the site for domestic/drinking water purposes. Based on recent analysis of groundwater samples from the onsite monitoring well (WSM-2),if the shallow or deeper aquifer groundwater resources at the site will be used in the future, groundwater quality analysis and evaluation should be performed prior to groundwater use. Carlton concluded that the presence of the observed site conditions fall within the category of"de minimis conditions." De minimis conditions are defined in ASTME 1527-05 as "conditions that generally do not present a threat to human health or the environment and that generally would not be the subject of an enforcement action if brought to the attention of appropriate governmental agencies" (Carlton,2008).The likelihood of hazardous materials or petroleum products impacts to the soil or groundwater at the site from onsite and offsite sources are considered to be low. However, some possibility of impacted soil and groundwater existing in areas not chemically analyzed must be recognized. The Phase I ESA revealed no recognized environmental conditions at the site as a result of past uses by WPCF;however,the four areas of environmental concern discussed above were identified. Three of these environmental concerns (onsite construction materials, surface deposits of gray silty material, and suspected oil staining) have been removed and/or disposed of properly. The fourth environmental concern regarding the use of the shallow,perched groundwater remains outstanding;however,according to the Phase I ESA, there is no immediate need to further assess the groundwater quality because of the future intended use of the property. The proposed power plant will get its process water supply from the WPCF, and all process wastewater from the LEC site will be disposed of on site in a new Class I underground injection well (UIW). Potable water will be supplied via a new onsite well.Further information regarding the UIW can be found in Section 5.15,Water Resources,subsection 5.15.1.5. The facility will produce no reclaimable process wastewater. For these reasons,there will be no groundwater use or discharges associated with the proposed project. A copy of the Final Phase I ESA is included in Appendix 5.14A. 5.14-2 SAC/371322/082330007(LEC_5.14_WASTE MANAGEMENT.DOC)