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081093 PK MINCITY OF SHOREWOOD PARK COMMISSION MEETING TUESDAY, AUGUST 10, 1993 MINUTES 1. CALL TO ORDER CONFERENCE ROOM 5755 COUNTRY CLUB ROAD 7:00 PM Chairman Dzurak called the meeting to order at 7:15 p.m. after the Commission perused additional information on Silverwood Park. 2. ROLL CALL Present: Chairman Dzurak, Commissioners Andrus, Fuller, Lindstrom, McCarty and Wilson (8:20); Council Liaison Benson; Administrator Hurm; Public Works Director Zdrazil; Park Planners Chamberlain and Schroeder; and Park Secretary Niccum Absent: Commissioner's Bensman and Laberee 3. REVIEW AGENDA Agenda was approved as written. 4. APPROVAL OF MINUTES McCarty moved, Fuller seconded, to approve the minutes of Tuesday, July 27, 1993, as corrected: Lindstrom requested that on page 2, paragraph 2, an addition be made to the minutes explaining that his main reason for preferring pea rock over sand was because he read an article a year or two stating that pea gravel is safer than sand. Motion carried - 6/0. 5. DISCUSSION ON USE OF SAND OR GRAVEL FOR PLAYGROUND EQUIPMENT Bruce Chamberlain, City Park Planner, reviewed his report of August 10, 1993. He said that the Minnesota Safety Commission tested shock - absorbing material by dropping it from increasing heights until deceleration exceeded 200 G's, at which point they felt a life threatening head injury could occur. This means that with 12" of playground cover, the following rate applies as shown: Washed sand 9' Pea gravel 10' Resilient surfacing 12' - 14' SHOREWOOD PARK COMMISSION MEETING TUESDAY, AUGUST 10, 1993 - Page two 5. DISCUSSION OF SAND VS. GRAVEL CONTINUED Chamberlain went on to say that: Washed Sand is the least expensive, but also the least safe. It requires resilient surfacing in certain areas to provide access for the handicapped. Pea rock is marginally safer than sand. It requires a geotextile fabric to prevent weeds. It also requires resilient surfacing in certain areas to provide access for the handicapped. Wood chips is safest. There is no need for resilient surfacing because it is fully handicapped accessible, however it is recommended that rubber mats be placed under slides and swings to prevent damage to geotech fabric as sometime happens when children kick feet and gradually dislodge chips in these areas. It is also necessary to install a fairly extensive drainage system to prevent saturation. Chamberlain asked Wilson the cost of cedar chips per ton. Wilson said it runs in the high $20, close to $30 range. Chamberlain and Zdrazil, using the same square footage, got price quotes. ZdrazilBs quotes were lower so they will be the ones used: washed sand Freeman Manor washed buckshot Freeman Manor 4.35 T. Delivered $ 965.70 + $ 1,700. for handicapped surfacing = $ 2,665.70 613.00 + $ 600. for handicapped surfacing = $ 1,213. $ 7.50 T. Delivered $ 1,650.00 + $ 1.700. for handicapped surfacing = 3,350. $ 1,100.00 + $ 600. for handicapped surfacing = $1,700. Lindstrom would like to see gravel because he feels it is safer. Zdrazil, when asked if geotech fabric was necessary, said he thought so, it is used to prevent contamination (a mixture of the soils). He said the City uses it as a road base so the gravel is not contaminated. Wilson agreed. Wilson said he hates to see the City spend any more money than necessary. He thinks sand should be used. SHOREWOOD PARK COMMISSION MEETING TUESDAY, AUGUST 10, 1993 - Page three McCarty moved, Wilson seconded, that geotech fabric be used, and that washed sand be used for the base. Motion failed - 3 ayes - 3 nays. McCarty moved, seconded by Wilson, that geotech fabric be used under the surface of the Freeman North playground equipment and the Manor playground equipment. Motion carried - 6/0. Lindstrom said gravel is cleaner, there are no cat problems, its safer, and its more aesthetically pleasing. Dzurak moved, seconded by McCarty, to recommend to the Council that pea rock be used as the playground base at Manor Park, and that sand be used as the playground base at Freeman Park. Motion carried - 6/0. 6. REPORT ON 1993 CONSTRUCTION PROJECTS Silverwood Tennis Courts Michael Schroeder, Park Planner, reviewed the report of August 9, 1993 (see attached). Schroeder said thereis a problem with the soils at the tennis court site because they vary in compressibility and in amount of frost heave action. He said the soil is also peat orientated, which means that as it drys out it will settle. One area has particularly good soils which will cause uneven settling. He said they have postponed the bidding indefinitely until a decision is made. He discussed various options: #1, Eliminate the tennis courts - he said if you put in other facilities, you can see what's done instead of spending a lot of money correcting a situation that cannot be seen. The Commission said that the proposed court area had already been subcut 3', and that 3' of clay had been put in. Schroeder said that the clay that was put in is excellent, but the depth and compressibility varies. The Commission asked if this meant it was not done correctly in the first place. Schroeder said it is likely due to the soil underneath. #2, Relo cate the Courts or Build on Court - would still involve further Also, it and this investigation of the soil, could mean that extensive could be very expensive. which would mean additional cost. retaining walls would be necessary, Schroeder said a lot of the suggestions in their report came from the geotechnical engineer, Mery Mindess. Shorewood's City Engineer, Joel Dresel, has worked with Mindess and respects his expertise and advice. The Commission asked the size of the area, so they can consider what else could be put into this area. Schroeder said it is a 1082 x 120' area. SHOREWOOD PARK COMMISSION MEETING TUESDAY, AUGUST 10, 1993 - Page four The Commission asked how deep the soil borings had gone down. Schroeder said some were 10' deep, some were 26' deep. Lindstrom asked what would happen if you added another foot of clay? Schroeder said he didn't think it would make any difference if it is the ground underneath the clay that is causing the current problem. Bensen said it could basically be a floating slab. He said if saw cuts were made, maybe eventually it would need some mud - jacking. It was mentioned that the court might not necessarily crack where the saw cuts are made. Wilson expressed concern over why the tennis court project got this far before it was discovered that there was a problem, and why this happened. It was suggested that the soil borings be done now for the tennis courts at Freeman Park to be sure that the soil there is adequate for tennis court construction. The question of how much soil preparation is planned for Freeman arose. The answer was just tree removal. Hurm said the Silverwood tennis court plans can be used at Freeman. The Commission said major problems seem to occur every time fill is used in the parks. The Commission and staff expressed deep concern over the fact that they have been telling residents for years that there will be tennis courts in Silverwood Park. Dzurak is going to speak with some of the neighbors. The Commission will continue discussion on this issue at the August 23 meeting where they will meet at Silverwood Park. Badger Project Hurm said the Badger bridge and trail are completed. Lindstrom said the walking path is very nice and suggested extending the trail and putting another bridge at the other end of the wooded area. The Commission said they had removed the suggested trail expansion from the park plan after walking it in the Spring and discovering that it is too wet. Lindstrom also asked what was going to be done with the bridge entrance because its all mud. Hurm said he would see if Tree Trust can do some transition work. Freeman Trails Hurm said the Tree Trust crew has been working on putting gravel on the trails in Freeman Park. He said the City was hoping Tree Trust would send out an adult crew to help assemble playground equipment. SHOREWOOD PARK COMMISSION MEETING TUESDAY, AUGUST 10, 1993 - Page five 7. REPORTS Tree Marking Wilson said he has gone out to Freeman Park and marked a few trees between the road and the wetland. He said he would be willing to donate trees. He said it would cost $500 a day for the equipment to move the trees, and from his nursery you could probably move 6 7 trees a day. He said there are a few good trees in the park that could be transplanted, he saw 2 nice sugar maples and some burr oaks. The Commission discussed combining donations and the transplantable trees in the park. Wilson said the trees can't be transplanted until October 1 when the ground is drier and firmer. He said the burr oaks should be done in the spring. Wilson also mentioned the two poplar trees behind the dugouts. He said each of them has a low branch that public works should trim off or the trunk will split eventually. Playqround Equipment Installation McCarty said the date for installing the playground equipment has been changed to September 18 and 19. She has the tool list needed for installation. She said everyone was supposed to bring certain tools. Public Works will be asked to supply the rest. Public Works Director Zdrazil will visit the site to see what needs to be done. The Commission reiterated that anyone interested in helping is welcome. 8. MATTERS FROM THE FLOOR Resignation - Mark Laberee Park Commissioner Mark Laberee called Administrator Hurm today and informed him that, due to a heavy workload, he was resigning from the commission . Chairman Dzurak asked staff to prepare a plaque for presentation to Laberee. Willow Tree in Road - Silverwood Park Dzurak reported that a willow tree has fallen on Silverwood Park property, along Covington Road, and asked that it be removed. 9. AD JOURNME N T McCarty moved, Lindstrom seconded, to adjourn the meeting of Tuesday, August 10, 1993, at 9:25 PM. Motion carried unanimously. RESPECTFULLY SUBMITTED Susan A. Niccum Park Secretary t Hoisington Koegler Group Inc. • M13 ® August 9, 1993 Mr. Jim Hurm, City Administrator City of Shorewood 5755 Country Club Road Shorewood, Minnesota 55331_ RE: Silverwood Park Dear Mr. Hurm: After reviewing the geotechnical report prepared by GME Consultants, Inc. for the tennis court construction, we have a concern for the long term integrity of the courts. There are several options for proceeding with the project which are discussed below. For now, however, we are postponing the bidding for this project until a complete understanding of the implications is reached, and we are able to determine the most appropriate course of action. • The geotechnical report states, in effect, that the underlying soils are not suitable for this facility without some remediation. The fill material and existing soils are highly compressible and subject to severe frost action. In addition, these conditions vary somewhat throughout the area of the proposed courts. Considerable differential settlement is the likely result, leading to surface irregularities, cracking and settlement estimated to be on the order of six inches. While these conditions do not preclude the construction of tennis courts at Silverwood Park, we have developed a range of alternatives for your consideration. 1. Eliminate the tennis courts from Silverwood Park, and identify other facilities that are better suited to these soils. Alternatives might include an open play area, or relocating the proposed play structure to allow for more flexibility in its use and development. The tennis courts might then be considered for another park in the community. 2. Relocate the tennis courts to a more suitable location within Silverwood Park. For this option, two configurations might be considered, however both would provide for only a single court. The single court might be moved to a location outside of the area of unsuitable soils, although this may require removal of some existing vegetation. The single court might also be oriented in an east -west configuration, which would situate it outside of the area of unsuitable soils, but with a less than desirable solar orientation. With either of these alternatives, further investigation of the soils would be required. Land Use/ Environmental ■ Planning/Design 7300 Metro Boulevard !Suite 525 • Minneapolis, Minnesota 55439 ■ (612) 835 -9960 ■ Fax: (612) 835 -3160 *.: J. Hurm August 8, 1993 Page 2 3. As described in the geotechnical report, build the tennis courts as planned and allow them to settle. After settlement occurs, the courts would be repaved to correct settlement problems. 4. As described in the geotechnical report, surcharge the area of the tennis courts and delay construction of the courts until the surcharge has provided its intended effects. Surcharging, as described in the geotechnical report, would involve placing five feet of fill material over the area of the tennis courts,and allowing the weight of that material to compact the soils below. The surcharge would result in conditions suitable for the tennis courts after a period of six months to one year. Costs for the four options vary greatly. Providing facilities better suited to these soils (without correction), as described in the Alternative 1, might be the most feasible - at least in terms of cost (all dollars spent would be for real, physical and usable improvements). It would require some study to define uses that could be provided in Silverwood Park, or to determine an alternative site for the tennis courts. Providing a single court in another location within Silverwood Park (as described in Alternative 2) would present costs somewhat less than the cost for installing two courts. Extra costs for tree removal, additional grading, retaining walls, subcutting poor soils, or even • surcharging might be expected. Additional soils investigations would also present extra costs. The costs of surcharging the court area (as described in Alternative 4) could result in costs of as much as $70,000 (see attached cost estimate). This would involve removing some unsuitable soil materials to approximately the frost depth, laying geotextile separation fabric, installing a subdrainage system, providing surcharge materials, and eventually removing the surplus surcharge material (all as described in the geotechnical report). After the surcharge is removed, the courts could be constructed over the surcharged surface. In our opinion, Alternative 3 is not reasonable or feasible. We recommend that you consider each of the other options and determine which best provides for the recreation needs of the community. We can proceed with improvements to Silverwood Park based on your direction relative to these concerns. Please call me if you have questions. Sincerely, Michael Schroeder, RLA • Silverwood Park Tennis Court Surcharge Cost Estimate August 6, 1993 Note: This estimate is preliminary, and cost could vary somewhat depending on availability of material in close proximity to the site. This cost estimate might be considered to be a "low end" estimate. 1. Excavate unsuitable soils to frost depth 150' x 138' x 3' deep = 2,300 cubic yards @ $6.00 /cubic yard $13,800 2. Place geotextile fabric 150' x 138' = 20,700 square feet @ $0.20 /square foot 4,140 3. Install subdrainage system (8 lines at 15' on center, each 110' long, with 120' connecting pipe, 3" p.v.c. with filter sock and drainage rock) 1,000 linear feet @ $1.50/linear foot 1,500 4. Place granular surcharge 150' x 138 'x 3' deep = 2,300 cubic yards @ $7.50 /cubic yard 17,250 5.. Place common surcharge [(150 ' x 138') + (120' x 108')] / 2 x 5' deep = 3,120 cubic yards @ $5.00 /cubic yard 15,600 6. Install silt fence at base of surcharge area 575 linear feet @ $3.00/linear foot 1,750 7. Remove surplus surcharge 3120 cubic yards x 80% = 2,500 cubic yards @ $6.00 cubic yard 15.000 TOTAL SURCHARGE COST $69,040 AUG 10 '531 17:47 OS11 MFL5, P 1P 1 F . 1 • August 10, 1993 Mr. James C. Hurm Administrator City of Shorewood 5755 Country Club Road Shorewood, MN 55331 Re: Tennis Courts Silverwood Park OSM Pile 5047.00 Dear Mr. Hurm: �lext lVlayeron & OM5XAS§0daU!S,1nC. 300 Park Place Center 5775 Wayzata Boulevard Minneapolis-ION 55416 -1328 612 -595 -5775 1 -806-753 -5775 F.a}C 595 -5774 Ent;ineerS Architects Planners Surveyors We have reviewed the soil report dated August 4, 1993 prepared by Mery ?vfindess and the summary letter dated August 9, 1993 by Michael Schroeder regarding the soil corrections for the Silverwood Tennis courts. We cannot disagree with the Findings of the soil report that substantial soil correction will be required to provide a long lasting, usable product. Regardless of whether the court area is surcharged or not, Mr. Ivlindess is recommending a three (3) foot subcut of the existin; soils, with a "clean" sand replacement and drainage system in addition to the usual aggregate base and asphalt surfacing. These items cover items 1, 2, 3, and 4 ($36,590) of Mr. Schroeder's letter. Surcharging - which is, essentially, piling soil over the construction area - was recommended to help prevent future settlements. Because surcharging is usually effective (and could possibly be done by public works), we highly recommend this option. The cost for surcharging, if done by contract forces with material supplied by them, would likely cost at least $30,600 as delineated by items 5 and 7 in Schroeder's letter. If the City is willing to assume some risk and future maintenance costs, some combination of the following items could be considered: 1) Reduce the amount of subcutting. This not only reduces the amount of excavation, but also reduces the quantity of granular suborade material required. It also greatly increases the likelihood of frost heaving. 2) Use the excavated soil from the subcut as at least a part of the surcharge material. This material will still have to be hauled out, but this eliminates a part of the cost of buying surcharge material. 3) Reduce the effects of settlement by constructing the two courts independently from each other. In other words, leave a joint between the two pads to allow a natural path for controlled cracking. Sawcutting along the net lines for the same result could also be done. This will require future joint seal maintenance. Hoisington Koegler Group Inc. H IC $ i MEMORANDUM August 10, 1993 To: Shorewood Park Commission From: Bruce Chamberlain, Park Planner Re: Discussion of playground surfacing alternatives. There are basically four products to choose from when surfacing playgrounds; sand, pea rock (buckshot), wood chips and rubberized resilient surface in critical areas. Issues to consider when making a determination are safety, durability, price, ease of installation and negative side effects of a product such as kids throwing rocks, etc. The standard depth of the three primary products is 12 inches. It is possible to decrease the depth of wood chips to a minimum of 8 inches but I would not recommended it for safety and maintenance reasons. DISCUSSION Sand: Washed, fine sand is the least expensive of the three alternatives at roughly $0.38 (depending on time of year and location) per square foot of play surface. Sand is also the least safe according to tests by the Consumer Products Safety Commission (greater than a 9 foot fall could result in head injuries). Obviously, it will not rot or degrade but it does need replenishing after several years due to kids tracking it out of the play area. There can be a health problem when cats use the play area as a litter box and there can also be problems with kids getting sand in their eyes. Sand does not meet handicapped accessibility standards. Therefore, resilient surfacing must be placed in critical areas of the playground to allow access to the equipment. This added cost should be factored into each playground as it is designed. Pea Rock: Pea rock is the middle of the road regarding cost at $0.58 (depending on time of year and location) per square foot. Pea Rock is marginally safer than sand (greater than a 10 foot fall could result in head injuries). It will not degrade from weather but needs replenishing due to it being tracked out of the play area. It also requires geotextile fabric to keep weeds from growing through it. There is a • maintenance problem because it gets kicked and thrown out of the play area resulting in greater need for replenishment and possible damage to park maintenance equipment. As with sand, resilient surfacing is needed in critical areas for handicapped access. Land Use/ Environmental ■ Planning/Design 7300 Metro Boulevard /Suite 525 0 Minneapolis, Minnesota 55439 ■ (612) 835 -9960 ■ Fax: (612) 835 -3160 Shorewood Park Commission August 10, 1993 page 2 Wood Chips: Wood chips, if prepared properly is a very safe surface for playgrounds (greater than a 12 foot fall could result in head injuries). The cost is high compared to sand and rock not only because of the product but because a fairly extensive drainage system is necessary to keep it from being saturated. The cost of a product called Fibar which is specially made for play surfaces is $2.97 per square foot including the drainage system. Rubber mats are also recommended under slides and swings at a cost of roughly $160 per mat. This product is also fully handicapped accessible so there is no need for resilient surfacing. It is necessary to replenish the product after several years. It will not easily burn because it stays moist just below the surface. Through my observation of play areas with this surfacing, I find it to be an excellent surface. It is very soft, mats almost like a carpet, does not get kicked around and makes the playground generally more pleasant to be in than ones with sand or rock. The cost is the difficult factor. Resilient Surface: This product is either poured in place or applied in square sections. It requires a bituminous or concrete base. It is very safe (roughly equal to or slightly better than wood chips) if applied in thickness greater than 2 inches. The cost is extremely high at $10.00 to $20.00 per square foot installed. For this reason it is • usually only used for handicapped access areas of the playground. COMPARISON Following are cost comparisons for Freeman and Manor Parks using the various surfacing materials. The costs generally include all necessary items for each type of system including resilient surfacing for handicapped access, mats under slides and swings, etc. Costs for rubber resilient surfacing under the entire play area in not included because of cost. Costs are rounded off and do not include tax. Freeman Park: Sand $3,400 Pea Rock $4,600 Wood Chips ( Fibar System) $14,600 Manor Park: Sand $1,667 Pea Rock $2,434 Wood Chips ( Fibar System) $9,000 PLAYGROUND SURFACING ioperties of such surfaces. Accordingly, CPSC conducted ests to determine the shock - absorbing properties of typical nose -fill surfacing materials in accordance with an ASTM* est method (ASTM F355 -86) that uses such a headform. he headform was dropped onto each surface material from acreasing heights until either the peak deceleration exceeded W G's or the HIC exceeded 1,000. Determination of Critical Height surfaces under a piece of playground equipment should have hock - absorbing properties sufficient to reduce, the likeli- hood of serious head injury if a child falls from the highest ►oint on the equipment. However, use of a given material at he appropriate depth cannot be expected to prevent or educe the severity of all injuries due to falls (i.e., head as vell as other body parts). :'he Critical Heightfor each surface material is defined as the aaximum height from which the headform, upon impact, , ielded both a peak deceleration of less than 200 G's and a I f less than 1,000. Critical Height, therefore, may be dered as an approximation of the maximum fall height rom which a life- threatening injury may not be expected to occur. rest Results I e following table contains the results of tests to determine se relative shock absorbing properties of seven loosefill 2 materials commonly used for surfaces under and around playground equipment. The table provides the Critical Height (expressed in feet) for each of the surface materials tested. The table should be read as follows: If, for example, uncompressed wood mulch is used to a minimum depth of 6 inches, the Critical Height is 7 feet. If 9 inches of uncompressed wood mulch is used, the Critical Height is 10 feet. It should be noted that, for some materials, the Critical Height decreases when the material is compressed These values represent the relative rather than absolute performance of the surface materials tested and may be used as a guide in selecting the type and depth of loose -fill material providing the greatest degree of safety for equipment of various heights. The shock - absorbing properties of some surfaces, such as sand and mulch, may vary due to moisture, long term use, or lack of continued maintenance. The depth of any loose - filled surface could be reduced during use, resulting in different shock - absorbing properties. For these reasons, a margin of safety should be considered in selecting a type and depth of material for a specific use. Manufactured surfaces, such-as rubber matting materials, may also be suitable for use under and around playground equipment. Many manufacturers of such materials have had tests conducted to determine the shock- absorbing properties of their products. They should be contacted fqr specific information on the performance and cost of their individual products. Material CRITICAL HEIGHTS (IN FEET) OF TESTED MATERIALS Uncompressed Depth 61nch 91nch 12 Inch Compressed Depth 91nch Wood Mulch 7, 10 11 10 Double 6 10 11 7 Shredded Bark Mulch Uniform Wood Chips 6 7 >12 6 Fine Sand 5 5 9 5 Coarse Sand 5 5 6 4 Gravel 6 7 10 6 Medium Gravel 5 5 6 5 .STM is a scientific and technical organization located in Philadelphia, PA and is a major developer of voluntary consensus standards.