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E Representative cross sectional diagram Please provide a representative cross-sc~ctiunal <br />diagram of a typical monitoring well installation. Please note that piezometers may be adcyuate <br />for measurement of groundwater monitoring levels. <br />g. Length ol-ilonitoring The applicant has proposed monitoring groundwater elevations for a <br />period of 12 months following completion of the slurry wall installation. If aRer 12 or more <br />months of monitoring the applicant believes there is sufficient data to demonstrate that <br />groundwater monitoring is no longer needed at the site, the applicant may subnut a reyuest to the <br />Division to discontinue the groundwater-monitoring program. 'l he Division will review such <br />reyuest and dctcrninc if the reyuest may he grartted. <br />3. "fhc applicant has specified that the vclocity:utd volume of flows expected on site Irom a 100- <br />ycar flood event, as well as the elevation of the 1On-year h:tsc Hood event and its relation to the <br />elevation of the spillways artd I:rkeshorc berm is provided in the Conditional Letter of Map <br />Revision (CI.OMR) previously providexl. Please clarify where in the CLOMR this information is <br />located, or provide if not previously submitted. Also, please yuantify or characterize the <br />expected groundwater surface between the stream channel and the adjacent Iloodplain to the <br />north render such att even[. <br />4. 'The applicant has proposed installation of three (3) spillways along the riverside of the <br />reclaimed pond cmbartkntent(s)daring final reclamation. Please specify wherein the CLOMR <br />document the Division may find the criteria used to determine the number of spilways to install <br />in the reclaimed lake(s) and the spacing between spillways. Since the r•c~claimed lake;md slurry <br />wall installation will be adjacent to a reach of the St. Vrain River that is over I mile in Icrtgth, Qtc <br />applicant will need to verify the mtmbcr ofspillways needed and the spacing intcn•al needed to <br />ensure that floodwaters from a 100-year flood event will he disr:harged back safely to Bte main <br />channel of the St. Vrain River within a reasonable periai of time and also maintain the structural <br />integrity of the slurry wall installation as w•cll as the surrounding area. Plcasc respond. <br />5. Please commit to provtding an "As Built" certification from a registered, professional engineer <br />or other yualificd person within 6(1 days of completion of the embankment stabilization project <br />that the embankment stabilization has been completed according to the approved designs so as to <br />provide adcyuate protection against a bank-full stream flow event or from floodwaters resulting <br />from a l(>U-year llood event, whichever is greater. Also, the applicant will need to commit to <br />providing revised maps and engineering desigms for any significant changes rryuired due to <br />unforrsecn lield conditions. Please respond. <br />G. The applicant has specilicd two (2) distinct scenarios fur the height of r•iversrde embankment <br />w receive nprap installation, and these scenarios arc bascYl on the proximity of the St. 4'rain <br />River to the existing ponds. Please clarfy the criteria that the apphcant will use to dilTcrentiate <br />when each treatment will hr applied, and please annmit to providing nprap annonng or other <br />slope protcrtion measures for xny riverbank location that is not currently stable from either <br />vegetation or existing riprap or concrete installation. <br />