Laserfiche WebLink
Mr . Himanshu H . Mehta, P . E . <br /> 8 March 2011 <br /> Page 4 <br /> Geosyntec will conduct a complete round of groundwater level measurements coincident with <br /> each semi - annual groundwater sampling event . Depth to groundwater measurements will be <br /> recorded to the nearest 0 . 01 - 11 in each monitoring well , including existing monitoring wells and <br /> applicable City of Vero Beach wells (assumed up to 82 wells) . <br /> As a potential cost- savings measure at the site , we are proposing the use of Passive Diffusion <br /> Bag (PDB ) Samplers in wells sampled for exclusively for VOCs . The PDBs are an innovative <br /> sampling technique that consists of the deployment of a semi -permeable low-density <br /> polyethylene tube lab - filled with analyte - free water within the screened interval of a well . The <br /> technology is based on the principal of diffusion and that compounds will migrate from an area <br /> of high concentration to an area of low concentration until equilibrium is achieved . It is <br /> recommended that the PDBs be deployed in the well for a minimum of 14 days up to a maximum <br /> of one year prior to sample collection . Use of these samplers in lieu of traditional low- flow <br /> purging techniques will save labor time in the field . More detailed technical information can be <br /> provided upon request . Geosyntec anticipates utilizing PDB samplers in lieu of low- flow <br /> purging techniques at a number of proposed monitoring well locations ( if approved by the <br /> FDEP) . If PDBs are approved for use at the site by the FDEP, it is anticipated that up to 30 <br /> percent of the proposed labor budget will not be utilized . <br /> Phase 5 — Data Evaluation and Semi-Annual Reporting <br /> Under this task, Geosyntec will perform data evaluation activities for the CVOC plume <br /> monitoring reporting and prepare semi -annual reports (two) for submittal to FDEP . Data <br /> evaluation activities will include database management, data evaluation and screening , <br /> geographical information systems (GIS ) figure preparation , time trend analyses, and/or statistical <br /> data analyses . The results of groundwater sampling associated with the CVOC plume <br /> monitoring will be presented in a report supported by attachments containing Chain -of- Custody <br /> sheets, field notes and observations, water sampling logs, maps, graphs , analytical results , and <br /> any other applicable materials . The draft reports will be submitted to IRC SWDD for review <br /> prior to submittal to FDEP . Each final semi - annual report will be signed and sealed by a Florida <br /> registered professional engineer or geologist. <br /> SCHEDULE <br /> FDEP has requested that the County begin implementation of the required activities <br /> immediately . Geosyntec will initiate these activities within two weeks of receipt of notice to <br /> proceed from the County . We will conduct the groundwater monitoring and reporting activities <br /> on a semi -annual basis as described herein . The semi -annual groundwater monitoring events <br /> will be conducted tentatively in June and December 2011 . In addition , Geosyntec is tentatively <br /> scheduled to attend the 22 March 2011 County Commission meeting to present a project update . <br /> CCR11018/XRI 1016 . docx <br /> engineers ( scientists innovators <br />