2009-06-08_REVISION - M1997032 (22)

Home Browse Search

.COR-040000 Stormwater Management Plan • • Rainfall measurements or estimates (in inches) of the storm event which generated the sampled runoff; 0 The duration between the storm event sampled and the end of the previous measurable storm event; • An estimate of the size of the drainage area and an estimate of the runoff coefficient of the drainage area; and • An estimate of the total volume (in gallons) of the discharge sampled. 2) SampliragProcedures For facilities with holding ponds or other impoundments, sampling shall be performed at the outlet from the pond. If no discharge from the pond to surface waters occurs, then no sampling is necessary. If any process water mixes with stormwater, all of the water is considered to be process water and must be covered under a CDPS industrial wastewater discharge permit. All samples will be collected from the discharge resulting from a storm event that is greater than 0.1 inches in. magnitude and that occurs at least 72 hours from the previously measurable storm event. If the collection of a sample cannot be obtained occurring at least 72 hours from the previous measurable event, the sample must be taken from a storm event meeting conditions as close to these as possible, and Denison will submit with the monitoring report a description of why obtaining a sample at least 72 hours • following the previous measurable event was not possible. The grab sample will be taken during the first thirty minutes of the discharge. If the collection of a grab sample during the first thirty minutes in impracticable, a grab sample can be taken during the first hour of the discharge, and Denison will submit with the monitoring report a description of why a grab sample during the first thirty minutes was impracticable. The first two samples per discharge point must be taken between November 17, 2008 and December 31, 2009, and reported to the CDPHE with the next Annual Report. L Van 4 Shaft SWMP 18 Denison Mines (USA) Corp.