SITE INFORMATION AND CORRESPONDENCE CASE 2

Home Browse Search

Messers. Freitas and Gilton - 3 - 14 December 2005 low permeability zones have failed to perform as designed due to groundwater mounding. Please reevaluate the infiltration assumptions. o Please provide a water balance that demonstrates adequate containment capacity for the 100- year return period total annual precipitation, including consideration of at least the following: i. A minimum of two feet of freeboard in all ponds at all times; ii. Historical local evaporation data(monthly average values); iii. Local precipitation data with the 100-year return period annual total distributed monthly in accordance with mean monthly precipitation patterns; iv. Proposed wastewater loading rates distributed monthly in accordance with expected seasonal variations; v. Projected long-term percolation rates (including consideration of percolation from unlined ponds and the effects of solids plugging on all ponds); and vi. Projected irrigation rates in land application areas. • None of the maps in the RWD are drawn to scale. Please provide scale drawings of the site location, the location of wastewater treatment equipment,the recycling area, the lined treatment ponds and the percolation basins. • The proposed wastewater treatment system may generate nuisance odors and may not be able to comply with standard Discharge Specifications included in all WDRs. Please address the following items: o The Sequential Batch Reactor (SBR) wastewater treatment system may result in operational requirements that will directly conflict with requirements in the WDRs. For example,to prevent nuisance odors all wastewater ponds are required to maintain at least 1.0 mg/L of dissolved oxygen in the upper one foot of the water column, but the RWD proposes allowing the SBR ponds to go anoxic to provide denitrification. That process may produce odors. o The sludge storage basin may also generate odors if sludge is not dried quickly. Please describe how odors will be controlled when sludge is wasted. The method of sludge disposal must be better defined. • Will the Supervisory Control and Data Acquisition (SCADA) system include monitoring and high- level alarms for the wastewater lift stations? • The RWD states that the SBR ponds will be lined but does not provide detail on what the liner will be. For each pond (treatment or storage) and other waste containment structure, provide the following information. Discuss both existing and proposed ponds: o Identification (name) and function of the pond; o Surface area, depth, and volumetric capacity at two feet of freeboard; o Height (relative to surrounding grade), crest width, interior slope, and exterior slope of each berm or levee; o Materials used to construct each berm or levee; o Description of engineered liner, if any; W:\S1all\ObricnTtSm Joaquin\Oakwood_Lakd miW 1 Dec 05.doc