Loading...
HomeMy WebLinkAboutDewateringSHAW April 30, 2005 Mr. Bill Carlson REHS Town Of Vail Community Development 75 South Frontage Road Vail CO. 81657 Re: Vail Plaza. Hotel Dewatering Dear Bill, This letter is in response to the recent events of the substandard dewatering procedures that have occurred during the week of 4/30/05 at the Vail Plaza Hotel project: 1. We now have the pumping system hardwired into the electric panel. This will now allow us to pump without the interruption of refueling. 2. The current sump pit elevation was lowered by approximately five feet on 4/29/05. This caused quite a bit of turbidity in the effluent, resulting in an unsatisfactory discharge into Gore Creek. In the future, we will let the water settle for a minimum of eight hours before starting the sump pump. 3. There is now onsite a one weeks supply of filters ranging from 5 -25 microns. This also allows us to change filters without the shutdown of the filtering system. 4. As you obsererved on 4/28/05, the filtering system when running uninterrupted results in a satisfactory discharge. We have now staggered our lunch breaks to prevent the lack of supervisory attention needed to monitor the discharge, which was apparent on Friday the 29P. 5. We are installing more gravel dams on 5/2/05 to aid in the filtering of the silt before it reaches the new sump pit location. Bill, we at Shaw Construction are confident in our abilities to rectify the poor procedures that have happened in the past week. We have been pumping groundwater for about a month, and we need to be much more diligent in our monitoring of this process to prevent the incidents of this week. If there are any problems or questions, please feel free to contact me at the site. Thank you, Bill. ncerely Ja es Jr. pe endent Stormwater Inspection Report Permittee: Shaw Construction Inc. Cert. No. COR- 037405 Date: 04/29/2005 Facility: Vail Plaza Hotel Industrial Type: Construction Receiving Water: Middle Creek Facility Address: 100 E. Meadow Dr., Vail, Colorado 81657 Persons present: Jim Heid, Project Superintendent w /Shaw Construction Facility Representative(s) /Title(s): Jim Heid, Shaw Construction Inspector: Bill Carlson, Town of Vail Inspection Findings Records Review 1. Site development and project activities began in the fall, 2004. The Stormwater Management Plan (SWMP) and sedimentation control site plan was available in the site office for review. The SWMP civil engineering drawings illustrate stabilized construction entrances, installation of silt fencing and installation of a stormceptor drainage inlet and straw bale inlet protection stormwater pollution prevent BMPs 2. Inspections of BMPs have not been conducted on the site. Inspections must continue every 14 days, except during winter snow pack conditions where no melting is occurring, or when all construction activities are completed. The operator shall keep a record of inspections on site and have available for review. Uncontrolled releases of mud or muddy water or measurable quantities of sediment found off site, including sediment in Gore Creek, shall be recorded with a brief explanation as to the measures taken to prevent further releases as well as any measure taken to clean up the sediment that has left the site. This record shall be made available to the Town of Vail and/or the Colorado Department of Public Health and Environment. When all construction activities are completed but final stabilization has not been achieved due to a vegetation cover than has been planted but has not become established, inspections must be conducted at least once a month. Facility Inspection Note: All BMPs mentioned in the below findings must be installed according to specifications and design criteria outlined in the SWMP. These specifications and design criteria must meet best engineering practice requirements. 3. It was noted, observed and photographed during the inspection that BMPs were not implemented to prevent the discharge of sediments and soils into Gore Creek from ground water dewatering operations. Control of excessive suspended solids shall be undertaken as necessary to prevent them from reaching Gore Creek surface receiving waters and causing any further water deterioration. Total suspended solids can be reduced by filtering the discharge, by directing the water to a settling basin and allowing the solids to settle, or by developing a clear well and pumping from this structure in the case of groundwater discharges. 4. A visual observation of cloudy and turbid water in Gore Creek was noted during the inspection from sediment discharged from the project with visible accumulations along the edge of the creek near the outfall (see attached pictures). All sediment accumulated in Gore Creek must be removed with in seven (7) days. Note: A copy of the SWMP must be made available for review at the project site office.