2011-12-15_AgendaPacket - Laserfiche WebLink

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651 Hale Avenue North Oakdale, Minnesota 55128 telephone: 651.770.8448 facsimile: 651.770.2552 www.eorinc.com Date I December 7, 2011 To GLWMO Board of Commissioners cc I Tom Petersen, GLWMO Administrator From I Camilla Correll, Mike Majeski, Tom Miller Regarding I GLWMO Stormwater Monitoring Background At the July 21, 2011 Board Meeting, the GLWMO Board of Commissioners approved the scope submitted by FOR to conduct stormwater monitoring for the remainder of 2011. Collection of this monitoring data was recommended to strengthen the calibration of the P8 model which will be used for the GLWMO Watershed Restoration and Protection Plan (WRAPP). The original scope (dated July 19, 2011) assumed that two monitoring events would take place per month for a total of six events /samples. Following equipment installation, only two significant rainfall events were sampled due to limited precipitation events. Installation of Monitoring Equipment The GLWMO provided FOR with three Isco 6712 portable samplers with area velocity (A/) flow modules and probes to use for the stormwater monitoring project. Upon arrival, it was determined that samplers needed service before they could be used in the field. New pump tubing and internal desiccant packs were installed, and the external flow module desiccants were re- conditioned. All service work was performed by Mike Majeski (EOR). Reconnaissance of monitoring locations and installation of automated sampling equipment occurred on August 4th, 2011. In attendance were Mike Majeski (Field Technician, EOR), Tom Miller (Water Quality Modeler, EOR), Duane Schwartz (City of Roseville) and Tom Petersen ( GLWMO). Following brief site visits at several locations, it was decided equipment should be installed at the existing monitoring location at Galtier Avenue and at a new location off County Road B2 near the Roseville High School (Figure 1). The goal was to select monitoring sites that are representative of the entire watershed (e.g. reflect the typical land use of the watershed). The Galtier site was located beneath a manhole and equipment was installed within the 48" RCP pipe. The Isco sampler was hung from the manhole ring using a metal suspension harness. The Roseville High School site was located just north of County Road B2 where twin 48" RCP pipes discharge into the southeast lobe of Willow Pond. Monitoring equipment was installed in both the east (RHE) and west (RHW) RCP pipes and the Isco samplers were placed within steel security boxes placed above the flared end sections of the pipes. The steel security boxes were provided by the Ramsey Washington Metro Watershed District ( RWMWD). Tom Miller with FOR assisted with the equipment installation. At each site, an area velocity probe attached to a stainless steel plate was mounted to the invert of the pipe to measure level and velocity of stormwater. The sample tubing was subsequently attached to the downstream end of the AN probe. Lastly, a 12 volt deep cycle marine battery was used to power the sampling equipment. The first round of water quality samples was collected on August 17'h and the second round of samples was collected on October 13th. A lack of significant rain events while equipment was installed prevented additional sampling. All monitoring equipment was removed on November 16th, 2011 and brought to the RWMWD garage for storage. Emmons & Olivier Resources, Inc. water ( ecology I community