Laserfiche WebLink
APPENDIX A: MONITORING PLAN <br />Draft Water Quality Monitoring Plan <br />For <br />Main Relief Canal Pollution Control Structure <br />BMP Effectiveness Evaluation <br />Sampling Locations: <br />Inflow <br />and outflow <br />of the treatment system <br />Frequency of monitoring: <br />Seven <br />storm events <br />of varying intensity <br />Storm Events: Storm event flow in the Main Relief Canal is dictated by the opening of a water control <br />structure operated by the IRFWCD. Gates are opened an average of 20 times per year <br />and left open approximately 20% of the year. Typically a one -inch rainfall or greater will <br />result in a gate opening and discharge to the IRL. <br />Flow Measurements: <br />Parameters to be monitored: <br />Parameter <br />Total Cadmium <br />Total Chromium <br />Total Copper <br />Total Zinc <br />NO2+NO3 <br />TKN <br />Total Ammonia N <br />Total Phosphorus <br />Ortho Phosphate <br />TSS <br />Oil/Grease <br />Flow will be measured using ultrasonic or similar flow meters. <br />Detection Limit <br />1 ug/I <br />5 ug/I <br />5 ug/I <br />10 ug/I <br />0.1 mg/I <br />0.3 mg/I <br />0.05 mg/l <br />0.05 mg/l <br />0.05 mg/l <br />1 mg/l <br />1 mg/l <br />Method <br />Composite <br />Composite <br />Composite <br />Composite <br />Composite <br />Composite <br />Composite <br />Composite <br />Composite <br />Composite <br />Composite <br />BMP Effectiveness Evaluation <br />Vegetative material collected from the treatment system will be continuously quantified by recording a wet weight <br />and moisture content. Representative samples will be periodically collected and analyzed for total phosphorus and <br />total nitrogen on a dry -weight basis. The County will maintain a running log of the total weight of vegetative <br />material removed by the treatment system. It will maintain a running total of phosphorus and nitrogen removed on a <br />dry -weight basis. This information will be used to document credit towards achieving the TMDL for this basin. <br />The Main Relief Canal has a continuous flow discharge to the Indian River lagoon that averages approximately 50 <br />million gallons per day. During storm event periods radial control gates are opened to release flood waters stored in <br />approximately 150 miles of canal and ditch network in the 21,705 acre basin. Gate openings occur approximately <br />20 times per year and remain open 2,000 to 3,000 hours per year. Discharges following a gate opening can reach <br />400 cubic feet per second. Due to the characteristics of this unique discharge situation, the County proposes to <br />collect frequent grab samples from the influent to the vortex unit and from the effluent. Flow will be continuously <br />monitored so that a mass loading will be established from the concentration data following laboratory analysis of the <br />samples (see parameter list above). Since the focus is on particulate matter and its associated pollutants, we do not <br />recommend the conventional automated sampler with the small intake tubing. The typical intake tubing associated <br />with a sampler cannot pull a representative sample that contains the particulate load. The County proposes to <br />conduct a characterization of both the influent and effluent channels to determine the best sampling technique. We <br />will work with FDEP to develop the most appropriate sampling protocol to establish effectiveness monitoring. <br />DEP Agreement No. G0182, Attachment A, Page 10 of 10 <br />