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or.WW.« <br />OVARTWM , Minnesota pollution Control Agency <br />PHMA 296-8762 <br />GATE May 27, 1992 <br />TO : File <br />Rou Lori L.C. Frekot/Mask Wespetai�Mw <br />NSS <br />Water quality Division <br />sun.mcT Lake Elmo Onsites <br />STATE OF NI MSOTA <br />office Memorandum <br />Lori L.C. Frekot and Mark Wespetal from the Minnesota Pollution Control Agency <br />(MPCA) visited four undeveloped lots in Lake Elmo on May 27, 1992: lots #1,2,3 <br />and 4 in the development near Lake Demontreville on Highland Trail, Jim <br />McNamara building inspector from the city of Lake Elmo also attended. This <br />memo identifies what was observed, discussed and provides follow-up comments. <br />OBSERVATIONS <br />Elevated mounds have been constructed on each of the four homesites observed. <br />Curtain drains have been installed between and around the four undeveloped <br />sites. The curtain drain discharges to a catch basin which discharges to a <br />wetland. No water was draining at the time of the inspection, <br />A few shadow probe tests were done to evaluate the fill and the natural soils <br />in the area. Probe tests in the fill could only go down a few inches because <br />of compaction, but the fill is appears to be clean sand. No jar test was done <br />to determine the amount of fines. Probe tests in the natural soils near the <br />park indicated a water table at the surface. <br />Water measurements in the three piezometers on lot #3 indicated essentially no <br />water in the drains. <br />DISCUSSIONS <br />We discussed the situation with Mr. McNamara. In summary, a contractor <br />installed sand mounds on top of approximately 12' of swampy material. Water <br />was draining from the streetside portions of the mounds so curtain drains were <br />installed. Seepage still occurred and the curtain drains were reconstructed. <br />Since that time, water level testing inthe curtain drains has been below the <br />3' required separation distance to the proposed drainfieid. Measurements of the <br />curtain drains have been taken by the city and TKDA. No data was at the site <br />for our visit. <br />Last week, the contractor came to the site and replaced portions of the sand <br />mounds. The city was not informed and has filed a complaint to'the city <br />attorney. TKDA (the city's consulting firm) has recommended that the fill <br />material go through one freeze/thaw cycle before soil testing and construction <br />can begin. <br />Homeowners in the area are concerned that the curtain drains will collect <br />partially treated or raw sewage and discharge it to the park. <br />a'd ndno-'jium/ADou iaio Hoiin-riOd kiw Wdvs:vo 2s, is wnr <br />