Agenda - Council - 09/13/1982 - Special

Home

iI SUMMARY OF KEY ISSUES I I I I I I I I I I I ,I I I I I I Groundwater and Surface Water The ability to protect groundwater adequately and the consequences of failure to do so are the most serious issues associated with this site. A major objective of the WMA is to minimize jeopardy to the environment from landfills selected through the current siting process. In its review, the MPCA has required that all sites be lined and groundwater monitored; leachate collection has been required for most. The Ramsey site is unusual because additional measures (a second liner and collection system) were deemed necessary but also appropriate in order to provide adequate groundwater safeguards. The greatest possible danger associated with this site would be for leachate to somehow escape undetected through the dual collection and the monitoring sys- tems, and penetrate through the drift into deeper bedrock aquifers. However, the likelihood of this occurrence does not seem to be great. There are 1) the protection afforded by the technological safeguards--liner and collection sys- tems, 2) a groundwater monitoring network to quickly identify leakage, 3) a confining and largely impervious till layer beneath the site, 4) a confining bedrock layer, and 5) a fairly sharp gradient in surficial groundwater flow toward the Mississippi and Rum Rivers. Similarly, the MPCA found in its review that it is highly unlikely that the bedrock aquifers would be impacted by site development. There is a greater potential for contamination of the surficial groundwater. The techhological controls are intended primarily to protect this aquifer. Due to the risk of contamination, new domestic wells have been prohibited from using this aquifer for many years. The area i~ not agricultural and the aqui- fer is not likely to be a significant water source for livestock in the sur- rounding area. Some of the domestic wells within a mile of the site are believed to draw their water from the drift. While this till layer is composed of relatively impervious materials, it can be discontinuous, intersecting more permeable layers and pockets. Water bodies near the site could be impacted by bo~h surface water and ground- water contamination. It appears that both Sunfish Lake and the wetland complex at the southwest corner of the site are hydraulically connected with the sur- ficial groundwater. The risk of contamination of this aquifer was discussed above. Both water bodies could also be affected by surface water contamina- tion. A drainage plan will be necessary for the site that ensures contaminated surface water does not migrate off-site. Ramsey's comprehensive plan states that the city intends to adopt a shoreland management ordinance to implement the plan's environmental protection element. Tt~e ordinance would create a 1,000-foot shoreland management district around lakes such as Sunfish Lake. (No portions of the proposed fill area are within 1,000 feet of the lake.) The DNR may also recommend that a shoreland district be created for wetlands that were once classified as lakes, such as the wetland complex southwest of the site. The implications of such action are not clear. The state Shoreland Management Act is principally oriented toward managing residential development around the state's lakes and streams. Its application to wetland basins has little'his-- tory. Should the site ultimately fall within a management district for the adjacent wetland, this may only minimally affect the proposed landfill. On consultation,'DNR staff has indicated that a landfill could-be an acceptable development within a shoreland district, provided that requirements such as setbacks for buildings or road~ are met.