SITE INFORMATION AND CORRESPONDENCE

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Mr. Jeffrey Palumbo • -4- • 15 November 2005 (E) name and address of well driller; (F) year of well construction; (G) use of well (agricultural, domestic, stock watering, etc.); (H) depth and type of seals; (I) lithologic, geophysical, and other types of well logs, if available; and (J) water levels,pump tests,water quality, and other well data, if available. (4) Land Use—Current land use within one mile of the perimeter of the Unit, including: (A) types of land use (e.g., residential, commercial, industrial, agricultural, recreational, etc); (B) types of crops; (C) types of livestock; and (D) number and location of dwelling units. (5) G.W. Use—Current and estimated future use of ground water within one mile of the facility perimeter. 17. Title 27 §21760 Design Report and Operations Plan. Design drawings are provided for the leachate collection pipes,pond liner system and liner system on the side slopes. A California Civil Engineer or a Certified Engineering Geologist shall certify the design. Design comments are as follows: a. Please provide a water balance for evaporation pond system. As outlined in Comment No. 7, the ponds shall be designed, constructed and operated to prevent inundation or washout due to floods with a 100-year return period. Class II surface impoundments and related containment structures shall be constructed and maintained to prevent,to the greatest extent possible, inundation, erosion, slope failure,washout, and overtopping under 1000-year, 24-hour wet season precipitation conditions, and shall be designed to contain the 100-year wet season precipitation(in back to back wet seasons)without using the two feet of freeboard. b. Provide a thorough discussion of the proposed design (i.e. liner system, pond volume, LCRS). c. All Units shall be designed, constructed, and operated to ensure that wastes will be a minimum of 5 feet above the highest anticipated elevation of underlying groundwater [Title 27§20240(c)], including the capillary fringe. Based on the geotechnical study performed at the site in April 2005 the encountered groundwater in two of the borings advanced within the footprint of two of the ponds was 3.8 and 4.3 feet below grade surface. Elevation depicted on the topographical map is approximately 20 feet above msl, however,the design drawings show an elevation of 105 feet. Clarification needs to be provided regarding the elevation of the pond, waste and groundwater. Staff is concerned with the depth to groundwater relative to the waste. Title 27 states that the ponds waste shall be at a minimum of 5 feet above the highest anticipated groundwater. A one time study (May 2005, Geotechnical Study) does not meet the criteria. Historical data should be reviewed to determine what the highest anticipated groundwater is. The highest anticipated groundwater shall be the basis for the design. d. The double liner system shall be contiguous up the side slope. The drawings depict the secondary 40 mil liner stopping at the base of the evaporation pond. e. Unclear of the purpose of the 200 mil geonet at the bottom of the liner system below the 40 mil liner(Section B Leachate Collection Pipe Figure). The drawing entitled Liner