COMPLIANCE INFO_2023 - Laserfiche WebLink

Home Browse Search

DRAFT [TENTATIVE] WASTE DISCHARGE REQUIREMENTS ORDER R5-2023-OOXX 15 FORWARD, INC. FORWARD LANDFILL SAN JOAQUIN COUNTY Table 2—Seismic Analysis Earthquake Magnitude Peak Ground Return Acceleration Period Max Credible 6.7 0.13 g 1,000 (MCE) Years Max Probable 6.4 0.09 g 1,000 (MPE) Years See Glossary for definitions of terms and abbreviations in table. 44. Based on data from the nearest weather station (Stockton weather station number B00-8560), the Facility has an annual average precipitation of 14.27 inches, and a mean pan evaporation of 78.43 inches per year as measured from the Oakdale Woodward Dam. The nearest weather station is reflective of conditions at the Facility. 45. WMUs must be constructed to accommodate stormwater runoff from 24-hour precipitation events with a return period of 100 years for Class III WMUs, and a return period of 1,000 years for Class II WMUs (see Title 27, section 20320). According to National Oceanic and Atmospheric Administration's (NOAH) Precipitation Frequency Atlas 14, Volume 6 (rev. 2014), the Facility's 100-year and 1,000-year, 24-hour rainfall events are estimated to result in 3.58 and 4.92 inches of precipitation, respectively. Source: NOAA Precipitation Frequency Data Server (https:Hhdsc.nws.noaa.gov/hdsc/pfds). 46. Stormwater sedimentation basins are situated in the western portion of the Facility, as depicted in Attachment B. A proposed sedimentation basin is permitted in the current entrance and located on the eastern boundary of the Facility. Stormwater from the sedimentation basins is typically evaporated but may be discharged to North or South Forks of South Littlejohns Creek. The Facility is covered under the State Water Board's operative General Permit for Storm Water Discharges Associated with Industrial Activities, NPDES Permit No. CAS000001 (Industrial General Permit). 47. According to the Federal Emergency Management Agency's (FEMA) Flood Insurance Rate Map (https:Hmsc.fema.gov/portal), the Facility is not located within a 100-year floodplain, except for the South Fork of South Littlejohns Creek. Per Finding 17 the Discharger is currently realigning South Littlejohns Creek south of the site. The new channel is designed to carry the 100-year flood flows within its banks.