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3. Papke Variance Appeali iy 7 CITY OF 3 CHANHASSEN 690 COULTER DRIVE • P.O. BOX 147 • CHANHASSEN, MINNESOTA 55317 (612) 937 -1900 • FAX (612) 937 -5739 TO: Don Ashworth, City Manager 6j► City �mummmistrator Ind orsed 4- Moditie Rejected - Dat Date submitted to Commission FROM: Sharmin Al -Jaff, Planner II �Dnte submitted to Council DATE: December 28, 1993 SUBJ: Appeal decision of the Board of Adjustments and Appeals for Variance #93 -9, Jeff Papke - Request to Locate a Septic System 75 feet from the Edge of a Wetland . to Serve a Single Family Residence On November 22, 1993, the Board of Adjustn requesting a 75 foot wetland setback variance a wetland (Attachment #1). The Board moved to table action on the regarding the different options available versus sewer)(Attachment #2). Appeals reviewed a variance application a septic system 75 feet from the edge of and directed staff to gather information icipal utility services to the site (septic On December 13, 1993, the Board af Adjustments and Appeals reviewed staff's findings and moved to deny the variance. The,$oard of Adjustment2lnd Appeals did not give a specific reason as to why they denied the variance; however, considerable time was spent attempting to figure out if the septic system would fail and the affect it would have on Lake Minnewashta. Subsequent to the Board of Adjustments d appeal9;' e receive a formal request appealing the Board's decision ; (letter ,attached) w Jndezre city's existing policies an #ppeal must be formally heard h the - ,City Council. Although staff understands the concerns flf the Board, we believe that the positions` of the applicant are valid and that the variance -should be approved. Our primary point is that the city operates °under ; the . most .recent state guidelines for on -site systems and the owner must comply with these criteria to receive a permit. Staff is not in a position to second guess these design standards We can only assume that they will do what they M_A were designed to do which is to protect the lake `and public health and safety. Before any septic system is placed on the parcel it will have to meet all building code ' requirements and be approved by the Building Official. MEMORANDUM LI Papke Variance December 28, 1993 Page 2 Staff maintains their position by recommending approval of this variance for reasons outlined in the report (Attachments 1 and 2) with appropriate conditions. RECOMMENDATION NOTE: The variance is for a setback from the edge of the wetland for a septic system. All other issues must be resolved at the time of building permit approval as outlined below such as soil suitability, septic system design, etc. Staff recommends the Board of Adjustments and Appeals adopt the following motion: "The Board of Adjustments and Appeals approves Variance Request #93 -9 for a 75 foot wetland setback for the location of a septic system. The following conditions must be met at the time of building permit application: 1. Type III erosion control be maintained during the construction season along the edge of the wetland and until vegetation has been reestablished on all disturbed areas. All disturbed areas must be revegetated within two weeks after issuance of a Certificate of Occupancy. 2. The applicant shall obtain and meet all conditions of the Minnehaha Watershed District permit. 3. The applicant shall obtain a driveway access permit and meet all conditions of the Minnesota Department of Transportation. 4. The applicant shall obtain and meet all conditions of the Department of Natural Resources permit. 5. The applicant shall submit a septic system design prepared by a Minnesota Registered Soils Engineer before any development take place. The design must be approved by the Building Official. 6. There shall be no alterations below the 944.5 elevation. 7. The applicant shall be responsible for all attorney fees associated with reviewing and recording this variance. 8. This variance will expire within one year unless substantial action has taken place. The applicant may apply for an extension prior to the variance lapsing. 9. The wetland shall be delineated by a Registered Wetland Surveyor. , F Papke Variance December 28, 1993 Page 3 ' 10. The lowest elevation of a structure shall be 3 feet above the OHW of the wetland. BUILDING OFFICIAL RECOMMENDATION: ' 11. The applicant shall provide the following additional information to the Inspections ' Division for review: a. A registered survey showing contours at 12" intervals, the 944.5' OHW, the two ' proposed 50' by 100' on site sewage treatment sites, the proposed structure site, the proposed driveway and the proposed well site. ' b. Stakes on the property locating the 944.5 contour, on site sewage treatment sites, structure site, well and proposed driveway. C. Two borings on each on site sewage treatment site. ' d. An evaluation by a geotechnical firm of the proposed structure site. 12. Resource Engineering shall be retained to evaluate the design at the owner's expense. ' 13. The design must comply with all the requirements of the Individual Sewage Treatment Systems Standards, Chapter 7080; Chanhassen City Code Chapter 19, Article IV; and the ' recommendations of Resource Engineering." ATTACHMENTS ' 1. Letter from Jeff Papke and Dr. Clifford Gustafson dated January 5, 1994. 2. Staff report and minutes dated November 22, 1993. 3. Staff report and minutes dated December 13, 1993. 1 b =e I 1 JAN- 5 -94 DIED 13:04 ERA CHESTNUT REALTY FAX N0. 6124486581 January 5, 1994 City of Chanhassen 690 Coulter Drive Chanhassen, MN 55317 TO: City Council RE: Variance request for Gustafson Property Gentlemen, P. 02 Jeff Pdpke and Dr. Clifford and Carol Gustafson have requested a variance from the wetland setback requirements for an on -site sewer system. In spite of the fact that the City staff have recommended approval-of this variance the Board of Adjustments has denied our request. We are requesting that their decision be appealed to the City Council. Our rationale is simple. The property in question was mistakenly classified as wetlands approximately 20 years ago due to the false assumption that all of this site was below the high water mark of Lake Minnewashta. We have provided surveys that prove that a significant amount of land, at least 1.5 acres, is more than 1 foot above the high water mark. In fact, much of it is 4 feet above the high water mark. The City has no clear definition dis- tinguishing the difference between wetlands and lakeshore. The Minnesota DNR and Federal Government classify this property as lakeshore. This in- correct classification has created an undue hardship on this property since the City requires a 150 foot setback from wetlands and 75 foot setback from lakeshore for on -site sewer systems. This 75 foot setback is consistant with Carver County and the State of Minnesota requirements for lakes like Minnewashta. The City's own Engineer has already testified that an on -site sewer system on this property will not present an unusual risk to the lake so long as it is properly installed and maintained. We therefore ask that the City Council review and approve our variance request. Respectfully Yours, . aAml Dr. Cl' ford Gustaf on Jeff awke ATTACHMENT #1 1 d CITY OF A i�ATE: 11 -22 -1993 CHANHASSEN DATE: � SE #: 93 -9 VAR Al- Jaff/v STAFF REPORT Pa P ke Variance November 22, 1993 Page 2 APPLICABLE REGULATIONS I The Zoning Ordinance requires all septic and soil absorption systems to be setback a minimum of one hundred fifty (150) feet from the ordinary high water mark of a wetland. , ANALYSIS The site is a lot of record which was previously used as grazing fields for sheep. It is located ' north of Highway 5 and east, south, and west of Lake Minnewashta. The applicant is requesting a 75 foot wetland setback variance to locate a septic system 75 feet from the edge of a wetland. ' The septic system will be utilized for a single family residence. The zoning ordinance requires all septic and soil absorption systems to be setback a minimum of 150 feet of the OHW of a wetland. The wetland is classified as a Natural wetland with an OHW of 944.5. It is also , protected by the DNR. The DNR requires septic systems to be located 75 feet from the Ordinary High Water Mark of a lake, therefore, a DNR permit is not required. However, any activity below the OHW of Lake Minnewashta will require a DNR permit. ' The area located in the center of the peninsula is proposed to contain one septic site and one alternative site, a well, and a single family residence. The highest elevation on the site is 947.3. , The Carver County Soils Survey indicates that the dominant type of soil on the site is Sandy Lake Beaches. This type of soil generally has a water table within one foot. Also, limitations for use as septic tank filter fields are severe. Any septic system or structure built on this site ' must be designed by a registered soils engineer. The Flood Insurance Rate Map (FIRM) shows the site to be located within the 100 year flood , zone area (Al). The goal of this program is to minimize the threat to property resulting from flooding. The program restricts development in floodplains by preventing structures from being built at too low of an elevation. It also controls encroachment on the floodplain so its water. ' holding capacity is not reduced and properly located structures will not flood. The 100 year flood elevation for Lake Minnewashta is at 945 according to the FIRM Map. The map is not completely accurate, as there are some elevations on the site that are above the 945. The ' Minnehaha Creek Watershed District is the governing agency over this area. Any fill or alteration taking place below the 945 elevation will require a Watershed permit. nim roved driveway that accesses onto Highway 5. The a ' The site has an existing u p y g y applicant must obtain a driveway access permit from the Minnesota Department of Transportation and meet all their conditions. Also, any work on the driveway will require a wetland alteration permit from ' the city. Staff recognizes that the magnitude of possible problems with this site are significant and we have discussed them with the applicant. However, it is the applicant's intention to build on the site, hence a variance is required. I i 0 I L u r� i Papke Variance November 22, 1993 Page 3 Staff will highlight conditions and requirements which the applicant will have to meet when a building permit is applied for. The variance is for a setback from the edge of the wetland for a septic system. All other issues must be resolved at the time of building permit approval such as soil suitability, septic system design, etc. The Board of Adjustments and Appeals shall not recommend and the City Council shall not grant a variance unless they find the following facts: a. That the literal enforcement of this chapter would cause undue hardship. Undue hardship means that the property cannot be put to reasonable use because of its size, physical surroundings, shape or topography. Reasonable use includes a use made by a majority of comparable property within 500 feet of it. The intent of this provision is not to allow a proliferation of variances but to recognize that and develop neighborhoods pre - existing standards exist. Variances that blend with these pre - existing standards without departing downward from them meet this criteria. The hardship in this case is created by the physical surroundings of the site. Lake Minnewashta and wetlands surround the site completely, making the site unbuildable without a variance to the wetland setback for the location of the septic system. We have discussed the septic system setback with the DNR and they have indicated that a 75 foot setback is a safe distance, which is the setback they require. We were unable to find another similar situation surrounding the lake. The area west of the site has access to sewer, and the subdivision east of it was created after the adoption of the Zoning Ordinance and meet the requirements. b. The conditions upon which a petition for a variance is based are not generally applicable to other property within the same zoning classification. * The conditions upon which this petition for a variance is based are not generally applicable to other properties within the same zoning classification. They are unique to this site. C. The purpose of the variation is not based upon a desire to increase the value or income potential of the parcel of land. * The purpose of this variation is not based upon a desire to increase the value or income potential of the parcel but actually to allow the property owner to use it for building a single family home. d. The alleged difficulty or hardship is not a self created hardship. ZA' 11 Pa P ke Variance November 22, 1993 Page 4 The difficulty or hardship is not self - created. The hardship is a result of the physical surroundings of the site. Lake Minnewashta and wetlands surround the ' property, making it impossible to meet the required setbacks. e. The granting of the variance will not be detrimental to the public welfare or injurious to ' other land or improvements in the neighborhood in which the parcel is located. * Staff has attached conditions to this variance to insure granting of the variance ' would not be detrimental to the public welfare or injurious to other land or improvements in the neighborhood in which the parcel of land is located. 1 light and air to adjacent f. The proposed variation will not impair an adequate supply of g ht J property or substantially increase the congestion of the public streets or increases the ' danger of fire or endanger the public safety or substantially diminish or impair property values within the neighborhood. * The proposed variance will not impair an adequate supply of light and air to adjacent property or substantially increase the congestion of the public streets. It will not increase the traffic. , RECOMMENDATION I NOTE: The variance is for a setback from the edge of the wetland for a septic system. All other issues must be resolved at the time of building permit approval as outlined below I such as soil suitability, septic system design, etc. Staff recommends the Board of Adjustments and Appeals adopt the following motion: , "The Board of Adjustments and Appeals approves Variance Request #93 -9 for a 75 foot wetland setback for the location of a septic system. At the time of building permit application, the ' following conditions shall be met: 1. Type III erosion control be maintained during the construction season along the edge of the wetland and until vegetation has been reestablished on all disturbed areas. All disturbed areas must be revegetated within two weeks after issuance of a Certificate of Occupancy. ' 2. The applicant shall obtain and meet all conditions of the Minnehaha Watershed District permit. ' , _, to 1 F J Papke Variance November 22, 1993 Page 5 3. The applicant shall obtain a driveway access permit and meet _ all conditions of the Minnesota Department of Transportation. 4. The applicant shall obtain and meet all conditions of the Department of Natural Resources ' permit. 5. The applicant shall submit a septic system design prepared by a Minnesota Registered Soils Engineer before any development take place. The design must be approved by the Building Official. I 1 1 i 6. There shall be no alterations below the 944.5 elevation. 7. The applicant shall be responsible for all attorney fees associated with reviewing and recording this variance. 8. This variance will expire within one year unless substantial action has taken place. The applicant may apply for an extension prior to the variance lapsing. 9. The wetland shall be delineated by a Registered Wetland Surveyor. 10. The lowest elevation of a structure shall be 3 feet above the OHW of the wetland." 11. Building Official Recommendations: The applicant shall provide additional information to the Inspections Division for review. a. A registered survey showing contours at 12" intervals, the 944.5' OHW, the two proposed 50' by 100' on site sewage treatment sites, the proposed structure site, the proposed driveway and the proposed well site. b. Stakes on the property locating the 944.5 contour, on site sewage treatment sites, structure site, well and proposed driveway. C. Two borings on each on site sewage treatment site. d. An evaluation by a geotechnical fun of the proposed structure site." ATTACHMENTS 1. Graph explaining the roll of agencies involved in 100 Year Flood Elevation areas. 2. Aerial showing the location of the wetland on the site followed by a description of the wetland. 3. Carver County Soils Survey showing the location of the site and type of soils, followed by a description of the type of soil and building suitability. 4. Flood Insurance Rate Map showing the location of the site. " is .M M = = = M r = M = = = M = = = Who to Contact About Land and Water Development /Alteration Questions ACTIVITIES OUTSIDE OF WATER BASIN BOUNDARY -4— (WORK - ON - THE - UPLAND) Examplesof Activililm Building Setbacks Land Grading Vegetation Removal Sewage Treatment Water Supply Decks Benchmark (3) LOCAL UNITS OF GOVERNMENT County and City - Shoreland Ordinance - Roodpiain Ordinance -Wild & Scenic Rivers ordinance Watershed Districts Vlo rManogementOrganizations 100 -Year Flood Elevation (2) h*1ditdl who own or oonld Ind mlooer* to . r ' Odm at wetlaxlr) at watercoum itcum oor*act tiw apendet ftW In"Uocft" to bv*" aboa*r1; 11 lnd ax! waterreptkAkm EveryaDwcy may not Move tmpedllc rePY sUNfOAiy W —mmm-1111 WITHIN WATER BASIN A A (WORK - IN - THE - BED) E R FEDERALAGENCIES B A S I N O U N D A R Y (1) Examplos of Activillim- Filling Excavating Draining Structures (Bridges, Culverts. Outfolls) Docks Harbors /Marinas Retaining Walls Vegetation Control (including Chemicals) U.S. Army Corps of Engineers - Section 10 Permits - Section 404 Permits STATE AGENCIES BOUNDARY DNR- Division of Waters - Protected Waters Permits Water Appropriation Permits DNR- Ecological Services - Aquatic Plant Monagerne -nt Permits (Vegetation Control incluc hg Chemicals) Board of Water and Soil Resources (BWSR) -1991 Wetiand Conservation Act LOCAL UNITS OF GOVERNMENT Watershed Districts Water Management organizations Soll & Water Conservation District (SWCD) istrial -1991 Wetkx - d Conservation Act Vegetation Aquatic 61ar Grasses Bulrush/Cattail Ordinary High Water Level (OHW) (1) I - - - - -\ - ----------------- - -- -- 1. DNR AUTHORITY - the regulatory authority of the Minnesota 'n\ X DN2 is measured from the Ordinary High Water Level (OHW) which Is defined as the elevation delineating the highest water level which has been maintained for a sufficient period of time to leave evkience upon the landscape. Generally. it is the point where the natural vegetation changes from e a prminantly aquatic to terrestrial vegetation. The OHW Is elevation from which edo building and sewage setbacks are measured. O f CORPS AUTHORITY - the regulatory authority of the U.S. Army Corps of Engineers is determined after a water basin has been delineated (based on the bash soils, vegetation and hydrology) by Corps personnel. The regulatory authority of the Corps ends at the water basin boundary, including the aquatic fringe which may be above the OHW. Local units of government should also be contacted, but in most Instances. do not regulate activities within a basin. 2 The 100•year or regional flood is the record event in which there is a one- percent chance of being equaled or exceeded in any given year The 100 -year flood elevations higher than the oHW and is used to determine the boundaries of the floodplain, which is usually regulated by a local floodplain ordinance. r Average Water Level e '" %X Record Low Water Level (4) C1 I n &. A benchmark Is an established (or assumed) reference point or elevation most comrnoniy expressed in feet above mean sea level. Benchmarks are commonly used by surveyors and building officials to locate the OHW and 100 -year f lood elevations. WARNING: - %���� "duinope octiNty rckidnp mdntvmmo on wetkrcb may alfed a Imdownsn receipt of USDA b wfh under the 1985 Food Seaaily Act (FSA) as amended Bef ore can nwwWV any ocwty affec*V dam on your laid. concoct you local USDA -Sall Ccruorvallon SwAce and refer to t wk fact *Wet entitied'FSA Wo"arxt Deter nftftm and Agftulk re SwAce. (Moy. 1990)•. January 1992 M 4. The record low water level tlbstrates that actual bash water levels fluctuate, but the regulatory basin boundary or OHW does not. Y j f 4 «y f.- ,f �/ � 1 i _fit ►� -. .�� "�� ,r3' 1 i!� '� ..�� � i % ice h r ( a � _. ,mss �'� ?� y - � �` ��• 3 } =S ki x hd m 1 V #� r r l r i r _ .� A-' I II •� �� � S• � R � ' /> ' • y:. y � s T � ��dr a + i +roc Cc ., Y ^ f SS ••1r S ,r x hd m 1 V #� r r l r i r _ .� A-' I II •� �� � S• � R � ' /> ' • y:. y � s T � ��dr a + i +roc Cc ., t City of Chanhassen Wetland Observation Records Welland No.: I (Field Review): b- i o C il (Official Map) Location J T; 23u1 R; __Section On USGS NWI: ✓ Y N Observer Initials: CIL Date Visited: ( / 9 / 9 Z Picture Number(s)/Roll #: 3 - H M I Picture Nos.: Classification Wetland Type: MMT- (Cowardin); 3 (Circular 39) Wetland Location: Lakeside Headwaters Streamside Isolated (upland) Edge of Wetland Contour 944 ,5 ; varies City Class: (P)ristine ; (N)atural ✓— (A)g/Urban (U)tilized Watershed Characteristics Wetland Size: Total drainage area: acres acres Direct drainage area: acres Open water area: acres Vegetation .fir p �,,o s-,--� $ Dominant Plant Species: D Reed canary grass -T D Cattail 6-1 S �a) � A), M;�l ^_ � �Lw •tea%• �r�S Purple Loosestrife: (D)ominant; (A)bundant; (S) me; (I)ndividuals; (N)one Plant Diversity: No. Species Dominant -1; 2; 3-S• 7 Percent open water: 5S %> 1 1 1 I P" G J Land Use Influences Surrounding Land Use (Percent): . 3 ° �s Residenti� D, Rur. Commercial/Industrial Agricultural 500/6 Open Water ' (Z ° /b Wooded — Institutional 15% Vacant Field :- 20 'moo (describe below) - -fir 1 a f sv, dj, Hydrology Water Source: V Natural; ✓ Stormwater; Unknown ' Inflow: Stream; Ditch; ✓ Stormsewer. v Surface Outflow: ✓ Natural; Ditch; Culvert; None Sedimentation/Siltation: Y u--- ' Flooded - dead or dying trees: ✓ Y N Drains to , tom s -t,..6 Ly_ , M•,,, LA-A., ; (Direction; Wetland No.) i (C)ontinuously (S) asonally; (I)ntermittently; (R)arely Soil Classification Soil Type Abbv.: Soil Name: J Other Wildlife Observations: General Notes/Comments: Pw.,ot,* l ess¢�J re r I ' ., . L `,. �I l.,f. n p.. � s � fern r.;r .�-•� �y a J�M� t✓`! r�nti.. �+ Y.,t.- %= �-�' - u Section No. 8 Wetland Sketch; Photo Locations 1 4 N N. 5 8 va �` 9 �. 12 � F 13 16 Not to Scale I ICA � 12 2 Atal I xA 1 Sc -ile 1:15 840 WDOT cr.j. I j n;4ne4 CAIiVEN COUNTY, AIINNb -SOTA 29 t rl, c , Illoderatcl�' steep slo (1 ' `l , u t �es t . ( \\'„I i,1! Ilejdl� and ilav crops. I hc• steel 1 �I T lca. 1pro fileofSllid "lo.tnf }'slu/ull(Illsile \' ?t1 l',as1 \t) ' 11) percent. to 4 inches, very dart: ;rat (IUYU :.111 1,1 :uuc -:u;d: \teal:, line allot medium, granular structure; t, 1'v able; neutral; clear, \trli t i.Ill-1,ru\en (101'Lt a %_'1 lo ;l 10 inches, very dart: g c• u;t►•se sand; weak, tine, 91:111111:11' �l ructure ; luose ; calcareolls; clear, irregular. :i1d (Ii.c) III'lI 1� bou11clary. C -10 to 42 inches, grayish-brown (10Yit . _') cuail•se s:ikl :u,d� ' gravel; single grain; 100se; enh•ni - vows. The Al horizon ranges from loamy s:u I,1 " "ll -c " "1•`' I ": "" in tt-dure and from 4 to 8 inches in thickness. The It hc'ri is either very thin or is discontinuous. It 1'-111„0:; fr „111 course sand and coarse sandy 10-1111 to It"(' gavel and :n e ' Wind that contains soiree fines. In places Ibr nudorlcin material co11taills stokes, cobblestone`;, lj d ee0u 't'11 I'� 1e L le X iron x1111 rarl,ge. from neutral to slightly c I),v underlying material are calcareuns. :11i soils are much coarser textured :111d 11111011 S'hallo\ver ' in •:II I and gravel than the sume\chat etce:xit'el� drained Ustherville soils. They have a nnu•h Ihiuner surface i;1Ycr than the excessively drained Sandy coliuvi:i► land. Salida loamy sand, 18 to 40 percent slopes (ScFI.- 1 his soil is characterized by )arro\\• terr;ice esrar1)11 it'll I; and ir►•emila.r ridges, hills, and bluff's. 60110ra11y it Is orll\ 4 to 10 inches deep over sand and rlaVcl. i a f0\\ ama? rho �►n face is gravelly. Afa ly areas are dissected h� 1.>r0ad. llrrl ;•1111 iec. I'hl ­11 i.; very drou`'hty and is unfit I'm. cro1)s. \fnsr 111' is pastured Or -wooded. (C;lp;ll)ilitY unit \'lls I. woodland group 7; bnildill” site -1-onp : ) Sandy Colluvial Land Sandv colluvial land (Sc) consists of deep. s ;lnd.v. rubs slopiii- to moderately steep, ex1•essivelw drained s,1il nla- a'rial that leas been deposited at f he 11;ise 111' sleep - 1 „ l „, <. This ninivrial. occurs below bluff's in Ihr -11 I'liesotil .Pi\er Wallet. P;krts of it are dissected h\- (1001) ,''nlli0s. In nlan\ :u•ea- 1 iii•re are detrimental deposits of sand and _1';1\ eI front gullies that are cutting down front uearl,\ st0rprr slopes 0 ". 13). T his soil laterial is neutral or tili;;htly acid. Natural fel t Illtt . 1, 1<1�\. The inoisture- stonlare c:ipacitN' is 1 11:1\\ Uelleral�\ tills Illa(erial is not Axed for crops, because. i!. is drenl it\ and occurs as such odd - sired areils th;it it is not. rendily accessible. It. is suitable for pasture early in x1)1'111_ Controlling• erosion is a. serious problem. (Capa.- i)ilitN unit. 1� -1; \toodlancl roup6; building site group S� Sandy Lake Beaches Sano-ty lake beaches (Sk) surround lakes and old lake - l. >eals of former Likes. They \'al_\ ill width. In places they are some distance froul the present lakeshore, on low nar- r0\t r bee:; or bars that were pus hed up by ice. Areas Bear tAistint lakes are ( suhnlerned when the water is IIIg '1'lle soil iaterial varies in color and texture. and lacks profile. development. It is gerlerall\ dark colore to nlod- eralciv clad: e,,Iored coarse sand or loamy eoar';e sand. Ina few areas it is medium textured to moderately fine textured :111,1 is covered with a. thin mantle of 1l0at or ;Huck. The \cater table is _ high, depending oil tho seat oil ;11111 nearm ss to the L•lke. Dminage rail- -es front l'Xci­i\v to \el.\' poor. T111s soil HHirerl.il i:; ver\v low in fertility. It is Illildlc alkaline to sli_ acid. S ;iii(ty lake heachvs are not generally used for fariiiiii a. \last :ire;is snpport I thin stand of ( and a felt wil- lows. (('x11 ;11)il1tY tulit VIIs - : \t„odhuul group G: bllild- ir1_ ite „ •ronp 1H) Storden Series The SO'l-dell series consists of Veep, rolling to llilIv. \well - dra i Hed soils !flat formed in friahle. luny clav 10 ,1111 ol _hi i;il till. Tht-t� soil-, are in the uplz6ids,'n7aanll 111 Che \• eshTI1 P;111 of I he counf C. T he ilative vegetation \waz The snrfa0e laver is ver\- dark _'-ravish - brown. friable li,:uu.It issliehtll linll.Tllislaweriscloddv. The nnderlvin, material is li_llt olive - brown. friabele. 1 lav lounl , la i;il t ill. It• is lim\ ;Ind massive. \;li1n;11 I' rlilil\' is nl0aiuul. The 01 - a lllc- 111 arter ,1n)- t0nt is lHl•11i1n 1. Riuloll' is rapid. Perilleabilit is liloderale. area the ill 11s lure- sior;t r ,1p;lrit\ is Moderate. Water (I(1(­ 11 4)1 cntrr I in <,1i1 0 asilw. The conrrnrrat ioll of carboil in the 111•41fli!= 1'r the rates of h,1111 II1hItratit'll aild per - 11w;Ih1111 V. Th(• o -wk ary used for _ farm crops. ThON ;Are \\;.11 - 11iit Ic1 :111';11f;1. The strori_0r slopes are a -eel 111ainl\ frlr p;lst 111 r ;l red h ;tw crop.. 1H 1111s ,• soils are snapped \\ith Tester so i I s. TYpic;tl 1)rotil0 of �tordeii loan) (cult.iwated field: 16 percent s,Iolw: sec. 6.T. 117 -N., R. -26 11'.) : t,11 i1whes. very dark _ravish- brown. (10YIt 3!2) ivalli; Ookldy : friable \.•hell moist slightly plastic when \vet ; slightly ealeareuu-4: nhrullt, smooth boundary. C - -t; t.. -lam Owlies. light olive-brown ( 2.5Y 5/4) claw loam; mas- siv friable when nuiist, slightly plastic and sticky \\'lwil \vet: c-alcareous. The Al horizon ranges from loam to clay loam. It is generally slightly linty. In►t in places it is neutral. Me depth to limy ma- terial is tvIdually less than 12 inches. There are stones and Figure 13 .— Deposits of sand and gravel on Sandy collutial land. Salida soils in background. 74 Building site group 9 SOIL - SURVEY more than three stories are very severe. The substratum has poor to fair bearing capacity, poor to fair shear strength, high susceptibility to frost action, and low to high shrink- swell potential. Limitations for use as septic tank filter fields are severe. The water table is high, an permeability is moderate to moderately slow. .Many areas are suitable for wildlife habitat. Some would be suitable for parks and recreational areas. Building site group 11 This group consists of Alluvial land and soils of the Chaska, Comfrey, Oshawa, and Terril series. These soils are on flood plains. They vary in frequency of flooding and have a seasonal high water table. The areas that are seldom flooded are good for crops. Those that are frequently flooded are used mainly for pasture. These soils have very severe limitations as locations for residences or other buildings unless they are protected front flooding. Limitations for use as foundations of buildings of no more than three stories are very severe. The substratum has fair to poor bearing capacity, fair to poor shear strength, and low to high shrink -swell potential. Limitations for use as septic tank filter fields are severe. These soils would be suitable for parks, recreational areas, and wildlife sanctuaries. Areas that are seldom flooded would be suitable for campsites and picnic areas. This group consists of soils of the Biscay, Canisteo, Cordova, Mayer, and Webster series. These soils are poorly drained and medium textured to moderately fine textured. The slope range is 0 to 2 percent. The seasonal high water table is at a depth of 1 to 3 feet. Drained areas are very good for crops. Because of wetness, these soils have severe limitations as locations for residential and commercial developments. If they are to be used as building sites, artificial drainage is needed, and fill is needed to .deep the foundation above the waterline. These soils are sticky when wet and have poor trafficability if used as roads. Limitations for use as foundations of buildings of no more than three stories are severe. The substratum has fair to poor bearing capacity, fair to poor shear strength, high susceptibility to frost action, and low to high shrink -swell potential. Limitations for use as septic tank filter fields are severe. The water table is high, and permeability is moderate to moderately slow. It is easy to establish grass, sod, trees, and shrubs on these soils. Building site group 10 This group consists of Sandy lake beaches, Marsh, Peat and muck, and soils of the Canisteo, Glencoe, and Talcot series. All are poorly drained and very poorly drained soils in depressions. Unless artificially drained, they are seasonally ponded. The water table is within a depth of 1 foot. Drained areas are good for crops. Undrained areas are fair for wild hay and pasture. Because of wetness, these soils have very severe limita- tions for community developments. If they are to be used as building sites, drainage Is needed, and fill is needed to keep the foundation above the water line. The peat and muck soil material should be completely removed before the fill is added. These soils have poor trafficability if used as roads. Limitations for use as foundations of buildings of no Soils in Recreational Development The many lakes and streams in Carver County provide ample opportunity for fishing, hunting, swimming, and boating, and the wooded hills and valleys along the Alin - nesota River and its outlet streams provide ideal sites for picnic areas, campsites, paths, and trails. The information in the following paragraphs and in table 6 can be used as a guide in determining the suitability of sites in Carver County for recreational development. TABLE 6. Degree and kind of limitation for specified recreational uses Soil Play areas for intensive use Picnic areas for intensive use Buildings in recreational areas Paths and trails Camp areas for intensive use Alluvial land (AI) - - - -- Severe: occasional Moderate: occasional Very severe: occa- Moderate: occa- Severe: occasional flooding; seasonal flooding; seasonal sional flooding; sional flooding. flooding. high water table. high water table. seasonal high water table. Alluvial land, fre- Very severe: fre- Very severe: fre- Very severe: fre- Very severe: fre- Very severe: fre- quently flooded quent flooding; quent flooding; quent flooding; quent flooding; quent flooding; (Au). high water table. high water table. high water table. high water high water table. table. Biscay loam (6c) ------ Severe: poor drain- Severe: poor drain- Severe: poor drain- Severe: poor Severe: poor drain- age; high water age; high water age; high water drainage; sticky age; sticky when table; sticky when table. table. when wet. wet. wet. Biscay loam, sandy Severe: poor drain- Severe: poor drain- Severe: poor drain- Severe: poor Severe: poor drain - subsoil variant age; high water age; high water age; high water drainage; sticky age; sticky when (Bd). table; sticky when table. table. when wet. wet. wet. F _ g ag k"w t i= id I " , -- s .r r �� R`-� a :;y -� 7 F _ g ag k"w t i= id I " , -- s .r r �� R`-� w -� 7 F _ g ag k"w t i= id I " , -- s .r r �� KEY TO MAP 500 -Year Flood Boundary 100 -Year Flood Boundary Zone Designations* With Date of Identification - -e.g., 12/2/74 100 -Year Flood Boundary 500 -Year Flood Boundary Base Flood Elevation Line 513 With Elevation In Feet ** Base Flood Elevation in Feet (EL987) Where Uniform Within Zone ** Elevation Reference Mark RM7X Liver Mile * MIS • *Referenced to the National Geodetic Vertical Datum of 1929 *EXPLANATION OF ZONE DESIGNATIONS ZONE EXPLANATION A Areas of 100 -year flood; base flood elevations and flood hazard factors not determined. AO Areas of 100 -year shallow flooding where depths are between one (1) and three (3) feet; average depths of inundation are shown, but no flood hazard factors are determined. AH Areas of 100 -year shallow flooding where depths ,are between one (1) and three (3) feet; base flood elevations are shown, but no flood hazard factors are determined. AII-A30 Areas of 10.0 -year flood; base flood elevations and flood hazard factors determined. A99 Areas of 1 -year flood to be protected by flood protection system under construction; base flood elevations and flood hazard factors not determined. B Areas between limits of the 100 -year flood and 500 - year flood; or certain areas subject to 100 -year flood- ing with average depths less than one (1) foot or where the contributing drainage area is less than one square mile; or areas protected by levees from the base flood. (Medium shading) C Areas of minimal flooding. (No shading) D Areas of undetermined, but possible, flood hazards. V Areas of 100 -year coastal flood with velocity (wave action); base flood elevations and flood hazard factors not determined. M7 -V30 Areas of 100 -year coastal flood with valocity (wave action); base flood elevations and flood hazard factors determined. NOTES TO USER areas not on the wenW flood hazard areas (cones A and % ihay be protected by flood control structures. This map is for flood insurance purposes only; it does not neces- sarily show all areas subject to flooding in the community or :11 pianimetric features outside special flood hazard areas. 1'or adjoining map panels, see separately printed Index To Map Panels. INITIAL IDENTIFICATION: NOVEMBER 9. 1973 T FLOOD HAZARD BOUNDARY MAP REVISIONS: uo V9 1 076 r i 1 MEMORANDUM CITY OF cHANHasssN 690 COULTER DRIVE • P.O. BOX 147 • CHANHASSEN, MINNESOTA 55317 (612) 937 -1900 • FAX (612) 937 -5739 TO: Sharmin Al -Jaff, Planner I FROM: Steve A. Kirchman, Building OfficialI� DATE: November 19,1993 SUBJ: 93 -9 VAR (Papke) I was asked to review the proposed variance for part of Government Lot 5, Section 8, Township 116, Range 23, Carver County. Background: I visited the site on 8/6/93 with onsite sewage treatment designer Ron Olsen. A soil boring was done 1 a location where we thought the onsite sewage treatment system would be located. Analysis The results of the boring ii dicated the site at which the boring was done was suitable for "an onsite sewage treatment system. The site was very marginal;° "'moving it 10" any direction could render it unsuitable. I am unable to ;:;determine, based on the information provided, -if the two proposed sites contain acceptable soils. I cannot determine, from the,information provided, if the proposed sites are large„ enough. " '"Nori mal proposed sites for new developments f are 50' by 400'' 'T'hi"s" 5000' square" foot `area is mply "to provide for a wide range of variables (slope, soils, house size, topography, etc.)' . The Carver County Soil Survey in t6' the soil type at the proposed building and onsite sewage treatment sites is Sandy Lake ' Beaches. This type of soil has!`the lowest suitability rating for sewage treatment and building construction. The Sandy Lake Beach soil is bordered by Peat and Muck soil, a soil with even less suitability. It is likely that soils underlying the proposed structure, which will have to be slab on grade construction, will require correction in order to support the struq�ure. Soil corrections, if required, F S a h rmin Al -Jaff November 19, 1993 Page 2 will adversely impact the area available for onsite sewage treatment sites due to the oversizing which soil correction would entail. Recommendations: ' I would suggest that the Board of Appeals and Adjustments table consideration of this variance request until the applicant provides addition information to the Inspections Division for review. ' 1. A registered survey showing contours at 12" intervals, the 944.5' OHW, the two proposed 50' by 100 onsite sewage treatment sites, the proposed structure site, the proposed driveway and the proposed well site. 2. Stakes on the property locating the 944.5 contour, onsite sewage treatment sites, structure site, well and proposed driveway. 3. Two borings on each onsite sewage treatment site. 4. An evaluation by a geotechnical firm of the proposed structure site. I va r �..2 '.:. ���< S./ � �E [��•� -R '• � ti�, .. 'fi r✓' R � . t} 1 • vA �,,I ;Yr, ���. �� $.+^ '• � �� Y'7 YN11r), K� �/` J,s �' � l F � r` • g r• `' s woo oft low - i '� �' �� • �'�' tit : y.! � � 7• ' � Wg TER • SEWER i • UNIVERSITY OF MINNESOTA SOTQ LANDSCAPE i ARBORETUM r ;I f CHANHASSEN BOARD OF ADJUSTMENTS AND APPEALS REGULAR MEETING NOVEMBER 22 1993 Chairman Johnson called the meeting to order. MEMBERS PRESENT: Willard Johnson, Carol Watson and Mark Senn I• Steve Kirchman, Building STAFF PRESENT: Shaman Al -Jaff, Planner g Inspector; Dave Hempel, Asst. City Engineer; and Roger Knutson, City Attorney JEFF PAPKE, WETLAND SETBACK VARIANCE FOR THE PLAC EMENT OF A WETLAND ON ZONED RR. AND , MOUND SYSTEM 75 FEET FROM A _PROPERTY LOCATED ADJACENT TO THE SOUTHERN PORTION OF LAKE MINNEWASHTA JUST NORTH OF HIGHWAY 5. ' Sharmin Al -Jaff presented the staff report on this item. Johnson: Would the applicant wish to speak first? Jeff Papke: If there are questions, you can first. Do I have a chance to speak later? , Johnson: ...you wish to go later on than now? Jeff Papke: That would be fine. Johnson: Okay. Any neighbors here wish to speak? Anybody from the audience. Steve, you had recommendations here? Kirchman: Well, yes I did. I don't really like seeing an on site sewage treatment go on this location. But if he can show me he meets all the criteria for installing an on -site sewage treatment, well then we'll let him put in on -site sewage treatment. One of the criteria is a 150 foot setback. We are the only people, or the 150 foot setback is a Chanhassen criteria. ' It's not a statewide criteria. There is really no statewide criteria in areas that have to adopt DNR regulations, the setback is 75 feet. So DNR feels 75 is okay. You know whether it is or not is anybody's guess. Now Ron Olson who's a system designer and I and Carl Barke who's also a septic inspector for the city went out to the site in August of this year and did a boring on the site and based on the boring that we did, the site's, or there is room on the site for a septic system. It just squeaks by. The criteria is mottling has to be no less than 12 inches to the surface of the soil. Mottles are these gray and red globules that form in the presence of water and they indicate seasonal saturation. So the criteria is if you've got mottles at less than a foot, you cannot build a septic system. I observed mottles at 11 to 12 ' inches. It's an objective measurement. Somebody could possibly say 11. Another person could say 13. It kind of depends on the person looking at it. So where we did the one boring, which would be right about, based on the information that the measurements that I took when I was on the site, that one boring was right about there. A little bit farther north than that but anyway, based on that, the boring I took there, that boring, the soils there were suitable to put up a septic site in. Now I can't predict what will happen here or here or here or here. Typically as the grade goes down, the mottling comes up. The closer you get to water, the closer the mottling is to the surface. But I didn't do borings there. We did ' borings where we thought the most practical site for an on -site sewage treatment system was and based on what we saw, you could put one there. So based on that, I would have to say he's got place on that site he can put. Whether he can put them where he's got them shown, I don't know at the present time. If he is successful in getting the variance, before we would ' issue a building permit he would have to show to us that he has got two sites, each 50 x 100 on which two legal, on -site sewage treatments systems could be placed. He would have to do two borings on each site and on his primary site, the one he's going to use immediately, he'd have to do perc tests and if his perc tests fall within a certain range and his borings fall within the range I mentioned, he would be able to put an on -site sewage treatment. I can't say at this time whether those two sites he's got picked out are because I haven't seen any designs or any borings from that. Based on experience, it's going to be real close. He was at 11 to 12 on the site I showed you. He's going a little farther north, a little farther south so it may stay right at the same. It may start dropping. I don't know. It's going to be real close. It's close everywhere on the property but it is doable where I did the boring. ' Johnson: What's your setback from the buildings, for the building pad itself? . Kirchman: 20 feet from the building. In a mound, a mound has got a 10 foot wide, usually a 10 foot wide by 37 to 50 foot long bed and then it's got dikes that go down on each side of the bed. And the treatment area includes the dikes so the toes of the dikes have to be 20 feet away from the building and 20 feet away from your setbacks. But typically on fairly flat ground a system will be, depending on the size of the house because it varies on the size of the house, 37 to 42 feet wide on flat ground. The slower the perc rate, the wider it is and the more bedrooms you have, the wider it is because the bigger it is. So 20 feet from the building for the toe of the dike. Johnson: You require two sewer systems? Two mounds. Is two mounds required? Kirchman: Well, we don't sa y o mounds are r e q uired. They have to lay out two sites. If � the other site was acceptable for a trench system, which in this case it wouldn't be, they could put a trench system on but all we require is that they lay out two sites. Those sites have to be big enough to cover just about any situation and a 50 x 100 foot site is big enough ' to cover any situation be it a mound, be it a trench system, whatever. Johnson: What about the well setback from the house or the septic system? 2 t Board of Adjustments and Appeals - November 22, 1993 1 � I Kirchman: That's got to be 50 feet. 50 feet away from his alternate or his primary and it only has to be 3 feet away from the house, the well. ' Watson: Where is that planned to go? Are those two things we see on either end down there, are those where the potential septic areas are? ' Kirchman: This is a potential system and this is a potential system. I would assume that he has got, since he's got this tanks shown here, here and here, that he's planning on using this as his primary system. He would come out and go into that system like that. He's shown his well right here in the south side of the house. Right here. I don't believe this drawing's to scale but the scales on the full size drawing is 100, 1 inch equals 100 feet and he's got that ' distance. Jeff Papke: Well from either. Kirchman: From either system and from his house, yes. Watson: Where is the sanitary tart' sewer from here? Al -Jaff: They would be able to ... Here is sewer and here is water. ' Kirchman: Here's the peninsula right there. And one problem with that is the invert of the sewer is at 948 and I don't think he'd be able to get ... on the sewer. The property's at 947 so ' to get his 1/8 inch of fall into that, he'd. Watson: He'd need a pump. ' Kirchman: He'd need a pump, right. Watson: But the sewer is available to that property? Hempel: Not via gravity it's not. It would have to be an ejector pump. For that long a distance Steve, I don't know if that's practical in the first place or even possible I guess. Watson: How long? How far are we talking about? Hempel: This drawing here is 1 inch equals 200 scale drawing. Sewer actually goes along ' here. Excuse me. Actually goes along the lake I believe but anyway, the parcel, the house location is out in this area here and the sewer's back here approximately I'd say about 400 feet. So it's quite a distance from where the existing sanitary sewer is. -h 3 1 1 1 I Board of Adjustments and Appeals - November 22, 1993 Watson: But it is in fact available to the property? I mean do you consider that available or? Hempel: No, I would not consider that available. Watson: Because he has to put in a pump? Senn: Would you consider it to be ever available? Hempel: In that location? From a cost standpoint. Senn: No, I'm just saying if you're basing your premise on whether a pump was needed or not, will sewer ever be put in along there which would feed this house by gravity? Hempel: Probably not because of the area affected. Right now we have Crimson Bay. That's proposed to be served through the interceptor. The Bluff Creek Interceptor further to the east. This area, Lone Cedar, Arboretum is served through the interceptor line that runs along the lake and crosses through here. The cost to run the sanitary sewer from here to here and here would be born by that property owner and that cost of that would be pretty substantial. Steve, I don't know if it's even practical, can you do an ejector pump for that distance? Kirchman: - I don't know. I assume that you're going to have more than an ejector pump. It would be like a lift station. It would be a lift station more than an ejector pump. Watson: Have we ever required anyone to bring the sewer 400 feet to sewer their property? Has it been done? Hempel: A sanitary sewer system that would serve other properties, yes. That would serve future properties beyond this, yes we would. This circumstance though. Watson: An individual. Have we ever required an individual to bring the sewer 400 feet to their property? Hempel: I'm not aware of any at this, in the 5 years I've been with the city. Watermain at some point... Watson: Well we don't, I mean we can't be concerned about the financial aspects of it or whether you know it's complicated. That's really not an issue for us. What is an issue here would be the best system for the overall ecology of the lake and everything else. And so I'm not concerned about whether it would cost a lot of money to take it out there. I'm concerned 14 4 Board of Adjustments and Appeals - November 22, 1993 about whether it could in fact, or should in fact be served by the sanitary sewer system as opposed to on site septic. , Hempel: Well, for the right cost anything is I guess possible. The maintenance though aspect of a mini -lift station and so forth for the property owner, those are all things to think ' about as well. Senn: Let me ask you this. If the other sewer goes, will you ever be at a point that you're less than 400 feet? Hempel: Most likely not. The next connection point would be down here at Crimson Bay ' where the Arboretum comes out which is over this location here which is even further away. At that point we may have a little more depth on the sewer to be able to serve that area. Senn: So you may be able to do gravity. Hempel: For a portion, a closer portion, right. We may be able to get it further at a greater depth to serve that. But at this point, without going back and looking at our comprehensive plan, I couldn't answer that. , Watson: When will that sewer come to Crimson Bay? Hempel: That sewer will not be available to Crimson Bay until the area actually petitions for ' it through further subdivision and so forth. The area north of Crimson Bay, Tanadoona, Camp Tanadoona and so forth, there's been some speculation of sewer and water out in that ' area in the next 2 to 5 years. The Crimson Bay area, we don't foresee it for quite some time. Kirchman: Yeah, they all are new houses in there with new systems and who wants to... I Watson: Well and they're big houses on big lots. They made that decision so they'll probably not want to, not until they want to split up their property for taxes... ' Johnson: A gentleman in the white shirt, you had a question. Cal Haskin: I'm Cal Haskin, Chestnut Realty. I'm the realtor involved in the property. The sewer service and the water service is not contiguous to this property. There is one additional lot that I guess is between the subject property and the end of the existing sewer line. ' Watson: ...come up here... ' VA 5 1 `j fJ d Board of Adjustments and Appeals - November 22, 1993 Cal Haskin: Oh I'm sorry. Watson: Yeah, tell us who you are again. Cal Haskin: Cal Haskin, Chestnut Realty. The Cedarcrest Addition off to the west of the subject property contains apparently 4 lots. The sewer and water service ends at the intersection of Lots 1 and 2. So in other words the subject property does not own Lot 1 or have any access over Lot 1 to secure sewer and water service to the area. The subject property is within the MUSA service line but they'd have to have some kind of condemnation action done to grant access across Lot 1 over to the outlot, or what's on there as Government Lot #1. So this 3 1/2 acres does not include but is on that map as Lot #1. Watson: Well I understand that. I'm just. Cal Haskin: Yeah I understand but the logistics would involve having to somehow secure access over somebody else's lot and that's an existing, I believe there's a home there. There's a driveway. Al -Jaffa On? Hempel: Lot 2. Al -Jaffa Lot 2, yes. Cal Haskin: Is there one on Lot 1 as well? Al -Jaffa I don't believe so, no. No, there isn't. Watson: I think Lot 1 is a swimming pool. Hempel: Right. State Trunk Highway 5 does have sufficient right -of -way though I would think that you could extend utilities into the state right -of -way too. Johnson: On Lot 5, Shaimin on your picture. The road runs, does it run right where the dotted line is? Al -Jaffa Yes. t Johnson: So the lot is to the west of the...? 0 1 Board of Adjustments and Appeals - November 22, 1993 1 I J Al -Jaffa Yes it is. Johnson: So what I'm saying, when I was out there I was walking in the water... , Al -Jaffa The other that, if I may add, it's truly wet out there. I don't know what type of soils do you need in order to run a sewer and water line? I mean does that make any difference? Hempel: Soil correction can also always be employed. Again the cost factor is driven up. The impact to the wetlands in installing that sewer and water line out there is another thing to consider. However at some point when Highway 5 will be upgraded and widened through , that area, at that time there will be impacts to the wetlands in the area as well, to be taken into consideration so maybe at that time would be the appropriate time to extend the watermain right through there and possibly sanitary sewer is available to run by the parcel. ' Watson: But if you're concerned about the effect that sanitary sewer, extending sewer might have because it's so wet, that doesn't give me an awful lot of confidence about on -site septic ' either. You know about how that is going to function. I mean it's real hard to sit here and decide that what you're going to do is construction something which could in fact be very destructive. , Kirchman: Let me address this just a little bit. Do we have a blank one of these? The theory behind mounds is that the soils on the site aren't really good enough to treat the , effluent. So if you've got grade here and you've got a seasonally saturated water table say down here 12 inches down, by the time these effluents percolate through the soil, they don't ' have enough, there's not enough, the bacteria, once they get below this seasonally saturated level, they can't live and they can't treat the bacteria in the effluent. So in 12 inches there's not enough room here to treat that effluent. So the theory behind the mound is build a treatment system above the ground. Put your effluent into here and give it more room to percolate down before it hits the water so by the time it does hit those seasonally saturated tables, it has been treated. So basically what you're doing is you're building your sewage treatment system on top of the ground. If you have mottling at one foot, you've got to put in 2 feet of sand. If you have mottling at 2 feet, you'd have to put in 1 foot of sand. So based on how far down your water is, that is based on the height of your septic system above grade. , So the theory is that if you've got water at a foot, it's going to be treated as well as if you had water at 5 feet. Watson: So the mound, the height of the mound is determined by how far down that water is so that you know that the mound is high enough to in fact treat the water before it gets down into the seasonal water table? 1 1 1 J F �J F Board of Adjustments and Appeals - November 22, 1993 Kirchman: Before it gets into the water table, right. Right. So by the time it gets down there, you could drink it. Watson: You could effectively have Mt. Everest on the side of house? Kirchman: What? Watson: You could effectively have Mt. Everest on the side of your house too. Kirchman: Except, except that you only need 3 feet of separation and the minimum. Watson: Okay, so that only needs to be 2 feet. Kirchman: That's the maximum it will ever be to the bottom of the rock but then you've got a foot of rock and you've got a foot above that. So you're going to have a maximum height of the mound that would ever be would be 4 feet high. At it's highest point. I'm concerned about the treatment too and I don't think this in here but if it meets the criteria. Johnson: Boy I went to all these meetings way back in 1970 when we were putting the city sewer in as a city and there was so much screaming about us polluting the lakes, I even seen it in my own neighborhood where duplexes were running right on the surface something terrible. Watson: Well look at Lotus Lake. We aged it. Kirchman: And even now, we've got systems all over town that are just emptying into ravines and. Watson: ...when the Federal government helped us put mound systems all over the city? Remember we did. Kirchman: Yeah, we've got a couple of those. 3 or 4 of them. One right to the north of here but mound systems have been in use for quite some time. The soils aren't to say they work. Johnson: ...I can't vote on is we're going to make a bad system worst. Not the sewer system. I mean the pollution system. We hear so much about pollution. People are constantly ... as I understand it's getting worse up north. I don't have any property up north but those that I have associated with have property and they said their sewer systems are getting, well. 8 1 Board of Adjustments and Appeals - November 22, 1993 1 Kirchman: Well it is, and we might be getting a little off on the side here. We're not required to adopt and enforce this. The counties up north, the smaller counties, the big ' counties, they haven't adopted these requirements so you can build any kind of septic system you want. You've got ...because this is not a statewide code. We've adopted it It works real well as long as it's enforced correctly and we do enforce it correctly so. I guess all I can say ' at this point, if he does get the permit, the 150 foot I think is great because it gives us more to protect those lakes a little bit more but it is a local ordinance and if you give them a variance, what he puts in will meet the State governments. ' Johnson: On the average, what's the average height of this land above water level? How much of the land is above lake level? ' Kirchman: How many acres or? Watson: What's the overall elevation? , Al -Jaff: The highest is at 47 so 2 feet. 3 feet higher. I Watson: It's fascinating to be out there. Johnson: Yeah I walked the whole roe P P rtY . Senn: Yeah, the other thing is the lakes are higher than they've been in years too. ' Watson: But we can't, we have to figure as high as they might get. 's year exceeded the ordinary ' Senn: I understand that but the lakes tlu y ary water mark. I mean that's something you have to keep in mind. Johnson: What's to say it won't keep on this way for a number of years. Kirchman: These mottles will form after about a year. If you get water in there and it sits in ' there for about a year, you'll start getting mottles and they'll stay in there forever once the water recedes. So if it had never been any higher, anytime from here until the—supposedly , you wouldn't be able to tell. So has it ever been to the height, that's one of the arguments contractors have is they say well, this pond is built over here and they say well the level of the water is no longer a valid measurement. Well, maybe it is, maybe it isn't. We don't , know that. We see the mottling there. You build 3 feet above that period because that's what the code says so. Theoretically if the water has ever been higher, we should be able to tell that. Based on the boring I did, it wasn't. I � 9 ' Board of Adjustments and Appeals - November 22, 1993 Watson: When we have one of those 100 year storms like we did that July where we got 13 inches or whatever it was, how does a sudden influx of a tremendous amount of water affect ' the mound? Kirchman: Well, it shouldn't affect it if it's built properly. The mound has a sandy loam cap on it and you do have to divert surface drainage away from it. So when you have a rainfall like the one you're talking about, most of that is going to run off and it will go around that. What does fall directly on the mound, the top of the mound has a sandy ... cap which doesn't i absorb as well as a lone cap and slushes it off to the side where it gets into the treatment area and then on out. So it shouldn't affect it if the mound is built correctly. Johnson: ...5 to 10 years before they get that—or maybe less. Hempel: It all depends on development pressure and as Steve had mentioned, those are very large homes. Newer homes so it could be longer. There's not vacant land. For them to subdivide those are ... where the Tanadoona - Dogwood area, there's some 40 -80 acre tracts of land that could develop here in the near future. Johnson: So it's coming this way? Hempel: Right. Johnson: Any other discussion? Do you wish to say something now? Jeff Papke: Sure. Johnson: Go ahead. Jeff Papke: I don't know if there are neighbors or anyone here. The reason we're asking for this is that we currently have a purchase agreement. I'm the ... tentative buyer of the property. One of the requirements is that the property is buildable so that's the reason we've gone through the sample borings and testing the property and surveying of the property was to fully ascertain ... the liquids form the septic system here that you're looking at and talking about, the solids as I understand are all pumped out ...and these are very prevalent systems throughout the Twin Cities. They've changed quite a bit over the years and are much cleaner nowadays... The site under most criteria, when we looked at the DNR criteria, we would not really have had an issue because they categorize this as a recreational development lake and given that criteria, the setback would be 75 feet. The City of Chanhassen, however has taken this small section of the lake and classified it as wetland. So that throws it into an entirely different category. Whether or not that is bonafide or not, I guess you're not here to contest zAo 10 Board of Adjustments and Appeals - November 22, 1993 1 L or discuss. But this is the only area of the lake that I understand is categorized as wetland and as such has more restrictive requirements than any other case. The elevation of the land is comparable to Red Cedar Point and some of the properties on the north shore of the lake. So in terms of elevation from the water, you're going to face much more than one property owner...if the lake ever goes 2 feet or 3 feet above the 100 year ... Our intentions are not to immediately break ground and start building... We're looking to purchases this and the sellers are anxious to sell. My wife and I view this as an opportunity to buy. We're not going to be breaking ground and building for a period of a few years but before we come to terms and agree to buy the land, I want to make sure it doesn't have to remain as ... it can be a buildable property at some point in the future before we commit our resources to this property. So I don't know if you have any questions of me? ' Johnson: Do you have any questions Carol? Watson: Well, Sham-An. Usually our variances don't last that long and in that interim period ' of time, if sanitary sewer were to become a viable possibility, I would like to see the mound system scrapped and have it attached to sanitary sewer. I mean if we're talking about say ' they're not going to build for 5 years or something like that. Johnson: The variance isn't any good then. , Watson: Well yeah so, I mean the problem is how can we give it for. Senn: Is a variance one year. Al -Jaff: Yes. , Senn: Well you can still give the variance. It's just good for a year. If they choose not to I exercise it, then they have to come through again. Al -Jaff: Anytime they request an extension you will review it. And Roger correct me if I'm I wrong. At the time of an extension can the Board add new conditions to a variance? Roger Knutson: No, they can just deny it. Deny the extension and thereby get it back in front of them and then add conditions or if they're no longer appropriate, deny the variance. Watson: So that would be our means. If we felt that sanitary sewer should be, go through would be to deny it and then have them come back and request that it. 11 ' 1 1 1 1 1 1 n Board of Adjustments and Appeals - November 22, 1993 Roger Knutson: Well right now for example you could impose a condition that says, if sanitary sewer's available, at the time they want to put in the septic system, they can't put it in. They've got to hook up. You could put that in as a condition right now. So I don't know the details of when it could go out there but let's say in the spring for, everyone was shocked but it got out there. And a month later the owner wanted to put in their septic system, by putting that condition in you could say no. You've got to hook up. Al -Jaffa Do you want to reduce the distance of how far? I mean currently we said it's approximately 300 to 400 feet? Hempel: Approximately. Watson: But yeah, see then you get to the point, what's considered available. Jeff Papke: The driveway itself is 300 feet long. So distance wise, unless you're angling all the way across the property in the wetland, the closest between two points, I don't think you could find a way of it being 400 feet. We were probably at least twice as long as that over the rest of it. Al -Jaff: And that's where staff is saying we don't think it would be feasible to hook up. Johnson: I hate to throw off ...if it's available to sewer and water. Say -it ain't feasible. Kirchman: That's not our determination. Johnson: Yeah. Because we're granting a variance on our ordinance. We're just throwing the whole 150 feet out, period. Let's knock it down. Watson: But we came up with that ordinance for reasons. Al -Jaffa Correct. I've questioned the ordinance lately. I mean it requires a 75 foot setback from the edge of the lake but 150 foot setback from a wetland. Watson: But if the ordinance needs to be revised, we revise the ordinance. We don't find a way to take a trip around it. Al -Jaffa No, absolutely. Absolutely. But like I said, the DNR is comfortable with it and they said it's a satisfactory setback. It's what they use throughout the state. 12 Board of Adjustments and Appeals - November 22, 1993 Johnson: I go along with Carol. If we feel the 150 foot is wrong, then we should change the ordinance before it circumvents... , Senn: Well just because our's is different than the State isn't necessarily reason to say it's wrong. I mean there are counties and cities throughout the state that have more restrictive... ' Watson: Like us. Senn: I mean we're not the only ones. I can tell you that ' Se Y Y Watson: No. No, we don't necessarily want to change it but I mean we certainly don't want ' to make policy of just finding a way around it either. Senn: Let me try something. This I think has the wonderful appearance of one that could go ' on forever. Given it is a lot and given that it is buildable, you know which seems to be fairly well defined. I mean those aren't questionable at this point. Jeff Papke: To the city inspectors. Senn: Yeah, that's right I mean that's something that's really determined outside of us. ' Outside of our process. After listening to everything, I still want to say no and just say no until sewer service comes in. You know. And that to me seems to be the easiest thing to say ' and at that point the owner or the applicant has every right in the world to put a house there because there's a sewer system and there's no reason why they shouldn't be able to. And I wouldn't be opposed to that at the point that it did have sewer. The only potential ' compromise I could see, I guess that I could live with and test the waters and see what you two think of it, is that the, that we would agree to the variance if the applicant would agree to install an enclosed system and agrees to hook to Crimson Bay sewer as soon as it's available ' or put in sewer at the time that Highway 5 is expanded, whichever occurs first. Watson: Now closest was one that's pumped. I Senn: Correct. Watson: At all times. Senn: Correct. , Watson: It has no outlet. 13 1 1 f' 1 Board of Adjustments and Appeals - November 22, 1993 Senn: Yeah, and then as part of the approval we'd require some sort of annual fund by the applicant of a contract to pump that system to assure that it is pumped each year. Or as needed. I mean to me that eliminates any and all environmental concerns. It allows them to go ahead but it also sets a clear deadline of one of the two things to happen, which would automatically trigger it and again, cost is not our issue but one of those two things trigger in effect the applicant moving ahead. Now if at that time the applicant chooses to go over and hook into the existing line, it's 300 -400 feet away, I mean that's up to them but that's something they have to weigh in relationship to their decision or whatever to go forward. But they would be required to hook up to sewer eventually. Otherwise, I mean if the long tern, to me if the long term answer is this property can't be served by sewer, then my long term answer is. Watson: It's not buildable. Senn: It's not buildable and it shouldn't be granted a variance in this case. But it appears to me from what I'm hearing is there are some potential options there so it seems to me that the whole system would be the answer, or at least I'd be comfortable with the caveat that one of those two occur. Kirchman: I'd throw a monkey wrench in that. The code we've adopted, 7080, lists standard systems of which a trench and a mound are standard systems and it lists alternate systems. And it states that we should only allow alternate systems to go in when other systems won't work. That's not the exact wording obviously but you know here we have a situation that, or we may have a situation because understand I haven't looked at the designs of where they're putting their systems but if a mound system will work where they're proposing them to work, we're actually putting in a less desirable system by putting in a holding tank or a reduced area system or a, they also have some filter type systems. In the opinion of the code, we're putting in a lesser system if we put that in in lieu of a mound that is on a site that meets all the criteria. Senn: Why is it a lesser system? Kirchman: The reason for that, that they don't like holding tanks at all and that's one of the lesser of the lesser systems actually. Because of the—problem. You can pump your effluent out into a mound and when it doesn't work, what's going to happen is it's going to back up into your house. You pump it into a holding tank and you've got a problem with it, then you put a pipe in your holding tank and drop that over the hill and away she goes and nobody ever knows about it. We do have one system I think in town that's on a holding tank and we have continuous problems with them maintaining their pumping contract. Us getting the receipts. Getting a record keeping on it. It's been a real problem for us and. 14 Board of Adjustments and Appeals - November 22, 1993 11 ' i but the State used to Senn: Well the State, and maybe they've changed t b , at least in the outlying counties allow that as the alternate to a mound system and that sort of thing when you couldn't meet the requirements. You know the setback. Kirchman: A mound used to be called an alternate system. Senn: I understand that. Kirchman: It was an alternate system so it was in the same class as a holding tank at one time. Senn: But what the State regs used to say was if all else failed, a closed system or ' incinerator system, which was the other one at the time. Kirchman: Right, if all else fails. ' Senn: Fails, those two were the best route to go. ' Kirchman: That's correct but see here we don't have a situation where all else fails because if they meet the criteria of the mottling down deep enough and they've got enough area to do , it and they're got the right perc tests, by theory that, whatever's coming out of that mound's going to be, treated when we're done. Watson: But Steve it fails simply because it does not meet the ordinance. ' Kirchman: It fails because of the setbacks. Watson: That's right. Kirchman: But, so the question is, are we going to let them put in what's really a lesser system because it doesn't meet that setback and that's a question you've guys are going to have to answer. In our experience holding tanks have not been a good answer. ' Senn: So even though on the surface they're more environmentally sound, in practicality they're not. You're saying it's simply because of maintenance. ' Kirchman: That's correct. Simply because of maintenance. We don't have problems with ' tanks breaking out or anything like that. Watson: Technically sanitary sewer is available to this property? 15 1 11 11 Board of Adjustments and Appeals - November 22, 1993 Kirchman: Technically it is... Watson: That's right. Jeff Papke: Technically sanitary sewer is available in northern Minnesota from this system if you wanted to run it 300 miles. Watson: Yeah but we're talking, it's down the street. I mean. Jeff Papke: It's below grade. It's I think about 700 to 800 feet away across a wetland. Underneath Highway 5 where there isn't any right -of -way. I just don't think it's a viable option. The city in some of the correspondence to me, or actually to the sellers, has indicated that the water quality would be poor because it's a dead end line. The contractor who laid out the septic systems advised against a sewer system because of the grades. Because of the land that it would have to be laid in. Essentially you have to put in a sewer system below the light bulb and run it down underneath the surface of the grade at the bottom of the lake in order to get it laid. It's really impractical...so when you look at the ordinance and say well it's 150 feet. This is 75. There probably aren't a lot of pieces of property that meet this exception of the criteria. This has been a lot of record and taxed as such I might add for the current owners. Since 1962. For all intensive purposes treated as if it was a viable, buildable lot. Really it's only the difference in how Chanhassen categorizes this, having that segment of property as wetland rather than Lakeshore that causes this to be, if it was zoned or classified as shoreline like everything else around the lake is and the way the DNR categorizes it, we wouldn't have to have this meeting. Watson: Right, but we are in Chanhassen. And it is wetland. Jeff Papke: Well, based on the criteria that the DNR has, where the water is coming from the same source as the lake surrounding it, all the criteria the DNR had. I mean they don't categorize it that way. Is the criteria for Chanhassen that different? Watson: It's 75 feet different. Johnson: Does anybody else wish to speak of this? Any other discussion? I'll ask to close the public hearing. Senn moved, Watson seconded to close the public hearing. All voted in favor and the motion carried. The public hearing was closed. L -ff E Board of Adjustments and Appeals - November 22, 1993 1 Senn: To me I'm just really uncomfortable with the mound system because I understand all the theories involved but there's no hard data in front of us in terms of showing us the... Cooper R. Gustafson: May I say something? Johnson: We closed the public hearing but I'll let you speak. Cooper R. Gustafson: I am the owner of the ... land and when we purchased that land, we purchased it with the understanding that it was a buildable, we did pursue getting information from the city. They told us it a. Johnson: Give us your name and address sir. Cooper R. Gustafson: I'm Cooper R. Gustafson and formerly of 804 Buckingham Court. As of a week ago I'm now a resident of Eagan. When we sold our house out on Lake Town Road out at Chaska and we took this land as a partial down payment. A fairly substantial amount of the down payment. And we did it with the understanding and that Mr. Haskins ascertain from the city that we did have a very buildable, viable property. Otherwise it would not have been anywhere near worth the amount of money that was allotted to it. And we pursued everything based on that basis so we came to the city. Asked the questions. Received ' the answers and then... accordingly. I have been paying taxes. I pay taxes of 700 and some dollars on that piece of land. Prior to my buying it the taxes were $6,200.00 but it's based as an agricultural piece of property and is not, no mention whatsoever any place in the county of it being a wetland. It's just simply mentioned as ... I hope that we're not being held to criteria that's more stringent than any other piece of wetland. We meet the responsibility as far as treating the water so we don't pollute it. Nobody wants to, certainly wants to pollute anything. And that the property be held to the same criteria that would be held to any other properties along the lakeshore in the future once sewer comes by. Then I don't think we should have a problem. We should be allowed, as in Jeff's case to ... property but certainly in ' our case to sell this property. I guess it's vitally important to us. It represents... personally what it means to be able to sell this property. It's a...question, I understand but the point is this. That everything was done in good faith from the very beginning. We never, the city ' told us that it was, the people that were in the office at that time said it was a buildable site. All we had to do was meet the criteria as far as the drainage was concerned and the building of a sewer system and we've proven that that's all a viable thing. The mound system, you ' could have a normal hill there. I mean it wouldn't be a problem... create a hill. So I think that should be in there too. I'm just simply ask that this variance be granted... Johnson: Thank you sir ... a motion here. I'll make a motion for denial. 17 1 -n i i Board of Adjustments and Appeals - November 22, 1993 Watson: Until sanitary sewer? Johnson: Until sanitary sewer is available to the property. Watson: I'll second that. Johnson: Any more discussion? I Senn: Um. 1 Senn: Yeah see that's the part that bothers me. Watson: Can we get more data on those closed systems and stuff . Watson: I don't know why that doesn't work. Senn: I'd really rather, for whatever it's worth, see us get the information. It's easy to sit here and say we want to deny it. Then the question is, why are we denying it. Well if the answer is, is that we're denying it because it doesn't have sewer service and it doesn't meet the ordinance requirements, that's fine. Ordinance requirements are guidelines in my eyes and we do get variances from them but again, it seems to me we're being asked to consider something and make a determination and we don't have adequate information. Before we're being asked to determine whether we think we should bury, I think we should know whether the mound system is in fact a solid environmental answer and I think we should also, well like I say. Watson: The merits... Senn: Right. The merits of one versus the other and it seems to me we're just kind of throwing all that together here at the last minute and assuming well, that's all going to be decided later. I'm not comfortable with that. I'd rather get the information first before I'd go forward on that. Johnson: Do you withdraw your second? Watson: I'll withdraw. Johnson: I'll withdraw. 18 1 Board of Adjustments and Appeals - November 22, 1993 1 • have information on mounds stems and on Watson. I'll make a motion to table this until we a y closed systems and on what it would take to put the sanitary sewer there. I mean what are we actually talking about? What drop don't we have. How far away from gravity. What kind of a trunking system would be necessary for it to function on a sanitary sewer system. Senn: And could we include in that a specific analysis of a mound system on this site. Watson: Yeah, this site. Not just mound systems because we know they work in other places but here. Did you second? Senn: Yep, second. Johnson: Any more discussion? Watson moved, Senn seconded to table action on the variance request for placement of a mound system 75 feet from a wetland until further information is gathered regarding the different options available to this site. All voted in favor and the motion carried ' Watson moved, Senn seconded to approve the Minutes of the Board of Adjustments and Appeals dated October 11, 1993 as presented. All voted in favor and the motion carried. Watson moved, Senn seconded to adjourn the meeting. All voted in favor and the motion carried. The meeting was adjourned at 7:30 p.m Submitted by Sharmin Al -Jaff Planner I Prepared by Nann Opheim 19 u i I t ATTACHMENT #2 CITY OF CHANHASSEN 690 COULTER DRIVE • P.O. BOX 147 • CHANHASSEN, MINNESOTA 55317 (612) 937 -1900 • FAX (612) 937 -5739 TO: Board of Adjustments and Appeals FROM: Sharmin Al -Jaff, Planner I DATE: December 8,1993 SUBJ: Update on 93 -9 VAR (Papke). Variance Request to Locate a Septic System 75 feet from the Edge of a Wetland to Serve a Single Family Residence On November 22, 1993, the Board of Adjustmer and Appeals reviewed a variance application requesting a 75 foot wetland setback variance to licate a septic system 75 feet from the edge of a wetland (Attachment #1). The Board moved to table action on the variance request and directed staff to gather information regarding the different options available to ..provide municipal utility services to the site (septic versus sewer). Under Section 19 -41 of the Water, Sewer and Sewage Disposal Ordinance, a site must fall into one of these categories for the city to require them to hocik-up to sewer: ,v 1. The premise must be adjacent to a sewer of the city: = sewer system. Finding: The closest sewer line is separated from the subject site by a parcel 2. The site'i§ 4ocated in a block Finding: The site is a or to ad is extends. 3. The site is located within one hundred;ifty (150) feet of a sanitary sewer system. Finding: The closest sewer line is located approximately 650 feet from the site. The Board of Adjustments and Appeals spent considerable time attempting to determine the feasibility of requiring a sewer hook up. While this may have merit, it does not meet the current ordinance definition for feasibility and certainly seems impractical at best. Secondly, there seems MEMORANDUM i� F� f� Papke Variance December 8, 1993 ` Page 2 to be a presumption that an on -site disposal system will be ineffective. The city operates under the most recent state guidelines for on -site systems and the owner must comply with these criteria to get a permit. Staff is not in a position to second guess these design standards. We can only assume that they will do what they were designed to do which is to protect the lake and public health and safety. Before any septic system is placed on the parcel, it will have to meet all building code requirements, and be approved by the Building Official. Staff maintains their position by recommending approval of this variance for reasons outlined in the report (Attachment #1) with appropriate conditions: RECOMMENDATION NOTE: The variance is for a setback from the edge of the wetland for a septic system. All other issues must be resolved at the time of building permit approval as outlined below such as soil suitability, septic system design, etc. Staff recommends the Board of Adjustments and Appeals adopt the following motion: "The Board of Adjustments and Appeals approves Variance Request #93 -9 for a 75 foot wetland setback for ­the location of a septic system, with the following conditions: 1. Type III erosion control be maintained during the construction season along the edge of the wetland and until vegetation has been reestablished on all disturbed areas. All disturbed areas must be revegetated within two weeks after issuance of a Certificate of Occupancy. 2. The applicant shall obtain and meet all conditions of the Minnehaha Watershed District permit. 3. The applicant shall obtain a driveway access permit and meet all conditions of the Minnesota Department of Transportation. 4. The applicant shall obtain and meet all conditions of the Department of Natural Resources permit. 5. The applicant shall submit a septic system design prepared by a Minnesota Registered Soils Engineer before any development take place. The design must be approved by the Building Official. 6. There shall be no alterations below the 944.5 elevation. V e Papke Variance December 8, 1993 Page 3 7. The applicant shall be responsible for all attorney fees associated with reviewing and recording this variance. 8. This variance will expire within one year unless substantial action has taken place. The applicant may apply for an extension prior to the variance lapsing. 9. The wetland shall be delineated by a Registered Wetland Surveyor. 10. The lowest elevation of a structure shall be 3 feet above the OHW of the wetland. 11. Building Official Recommendations: I The applicant shall provide additional information to the Inspections Division for review. a. A registered survey showing contours at 12" intervals, the 944.5' OHW, the two proposed 50' by 100' on site sewage treatment sites, the proposed structure site, the proposed driveway and the proposed well site. b. Stakes on the property locating the 944.5 contour, on site sewage treatment sites, structure site, well and proposed driveway. C. Two borings on each on site sewage treatment site. d. An evaluation by a geotechnical firm of the proposed structure site. 12. Resource Engineering shall be retained to evaluate the design at the owner's expense. 13. The design must comply with all the requirements of the Individual Sewage Treatment Systems Standards, Chapter 7080; Chanhassen City Code Chapter 19, Article IV; and the recommendations of Resource Engineering." ATTACHMENTS 1. Memo from Building Official dated December 8, 1993. 2. Staff report dated November 22, 1993. 3. Plan showing location of sewer and water lines. 4. Minutes dated November 22, 1993. I U , CHANHASSEN MEMORANDUM TO: Sharmin Al -Jaff, Planner I FROM: Steve A. Kirchman, Building Official DATE: December 8, 1993 SUBJECT: 93 -9 VAR (Jeff Papke) I have been asked to comment on the request of Government Lot 5, Section 8, Township 11 ( to locate an onsite sewage treatment system v Background: CITY OF 690 COULTER DRIVE • P.O. BOX 147 • CHANHASSEN, MINNESOTA 55317 (612) 937 -1900 • FAX (612) 937 -5739 setback variance for a lot described as Part ;e 23, Carver County. The applicant wishes the required setback area. The variance request was heard by the Board of Adjustments and Appeals on November 22, 1993. Staff was directed by the Board t6' explore all possible onsite sewage treatment options. Onsite sewage treatment systems are regulated by Individual Sewage Treatment Systems Standards, Chapter 7080 as amended by the Chanhassen City Code. Analysis: I will outline treatment permitted in the code and the pros and cons of each. Holding Tanks. Holding °tanks are classified in the code and are ".::allowed only as replacements for existing existing parcels or lots as of the date of the enactment of it can conclusively be shown thata standard, Class cannot feasibly be nstalled. " (7080 0210. Sub" .6). Vhese City in January, 1987. as a Class IV,altpmative system nonconforming,Aystems or on these standards and only where 911, Class III, or mound system standards where adopted by the Pros. -Enables dwelling to be constructed on existing lot of record that has no available onsite sewage treatment sites. •Enables existing dwellings to remain in the event of the failure of the dwelling's current onsite sewage treatment system. E Sharmin Al -Jaff, Planner I December 8, 1993 Page 2 Cons. -Provides minimal treatment. Effluent must be trucked offsite and either land applied or introduced into the Metro Waste Control treatment system. This has the long term effect of reducing the sewer capacity of the City. -Expense. A typical family of three uses about 225 gallons of water per day. Pumping costs are about $100.00 per 1000 gallons. This represents a minimum monthly cost of $675.00. It is very ' difficult to devise controls to assure that the effluent is properly disposed of. Methods of reducing the monthly cost of disposal will inevitably be sought by most homeowners. Most methods will be illegal. •Installation cost. The holding tank for a three bedroom home must be 1200 gallons, but in most cases it will be sized in excess of 4000 gallons in order to provide decreased pumping frequency and increased safety margins. Tanks are emptied when pumped, and systems designed to prevent floatation must be incorporated into their design. -Road restrictions may prevent tank pumping for long periods. -Accidental discharges during pumpouts would have a negative effect on nearby bodies of water. I have included an illustration of a holding tank, which in most cases is a modified septic tank. Mound Systems. A mound system is classified as a standard system, and mounds or other standard systems are the required means of onsite sewage treatment when conditions permit. Onsite sewage treatment depends on bacteria in the soil for treatment, and the bacteria must have oxygen to survive. Suitable amounts of oxygen are not present in saturated soil for sewage treatment. Soil saturation is determined by mottles - a combination of red and gray deposits formed when soil is periodically saturated. Soil borings are done on the site to determine the depth to mottling, and the treatment system is designed to provide three feet of separation between the mottles and the bottom of the treatment system. Studies have shown that critical percentages of the viruses in the effluent of dwellings are digested in three feet. Additional separation does not appreciably add to treatment of viruses. Phosphates, which cause algae growth are not digested or destroyed by onsite sewage treatment systems. The three foot separation provides a large area for dispersal of the phosphates thereby minimizing environmental impact. Separations greater than three feet will aid in phosphate dispersal, but will have minimal effect on virus treatment. The critical element in onsite sewage treatment design is t accurate determination of mottling depth. The code permits systems to be built when mottles are as shallow as one foot (two feet of sand is added to provide separation). Mottling is sometimes difficult to determine at shallow depths, and color charts are used when red and gray colors are masked by natural soil color or vegetation. Most systems installed in Chanhassen since 1987 have been mounds, and very few problems have been experienced until this year. Staff has investigated three failures in the southeast part of the City that involved liquids surfacing at the toe of the downslope dikes. Preliminary indications are that the liquids are a combination of treated effluent and ground water. Surfacing has been attributed to improper landscaping and system overloading. A number of steps have been taken to reduce the chances of repeat occurrences. Needless to say, the system in question, if permitted, will be closely scrutinized. The City uses the services Sharmin Al -Jaff, Planner I December 8, 1993 Page 3 of Resource Engineering for onsite sewage treatment system evaluation when problemsor questions arise. Pros. -Standard system with a good track record. No rural developments since 1987 would have been permitted had not mound systems been developed for onsite sewage treatment. *Provides adequate treatment without trucking waste offsite. Cons. -Two required sites consume large areas of lots. -Pressure distribution required. I have included some diagrams of mounds to illustrate their appearance and construction. The applicant has not yet submitted a design for the system located where it is currently shown. Staff will perform an onsite evaluation, which includes borings, prior to issuing any permits to determine design acceptability. Recommendations: Staff recommends the following conditions be included if the variance is approved. 1. Resource Engineering shall be retained to evaluate the design at the owners expense. 2. The design must comply with all the requirements of the Individual Sewage Treatment Systems Standards, Chapter 7080; Chanhassen City Code Chapter 19, Article IV; and the recommendations of Resource Engineering. 1 1 Holding Tanks While holding tanks are not recommended for installation on newly developed lots, there are some developed lots which do not have adequate area for a sewage treatment system. If those lots are along a lakeshore, and the sewage is discharging to the ground surface or into a surface water, a holding tank may be the only alternative. Figure C -23 shows a schematic diagram of a holding tank together with the tank capacity as recommended by Chapter 7080. a t 4" PIPE FOR ACCESS TO INLET_ HOUSE 6" CLEANOU SEWER PIPE WITH TIGHT CAP 20" MANHOLE O TO 12" OF EARTH COVER. IF _1 COVER IS AT THE SURFACE IT MUST BE SECURED TO PREVENT UNAUTHORIZED ACCESS. TANK CAPACITY - 1,000 gallons minimum or 400 gallons per bedroom, whichever is greatest; for other establishments, 5 times the daily flow rate. TANK MUST BE WATERTIGHT WATER FLOWING INTO SEWAGE SYSTEM SHOULD BE METERED HOLDING TANK Figure C -23 Holding tanks may be allowed by the local unit of government as a solution to an existing problem situation or under unusual circumstances as a temporary system until connection can be made to a municipal sewer system. Holding tanks should be used only on developed lots where no other alternative methods of sewage disposal are feasible. The local unit of government must maintain adequate control of the operation of the holding tank to ensure that all sewage is adequately treated and disposed of L t 1 E -2 Many Minnesota counties have found that properly designed and constructed mounds are an effective method of sewage treatment and accept them as a standard system. Sewage treatment mounds should not be considered alternative treatment systems but rather preferred treatment systems, in many instances. Figures E -1 and E -2 show a perspective view as well as a cross- section and plan view of a mound. Mound construction begins with the layer of clean sand which must be at least Moot thick. The top of the clean sand layer must be level as must the rock layer which is placed upon the clean sand layer. Distribution pipes are placed in the clean rock. A sandy loam cap that is 6 inches thick at the side and 12 inches thick at the center is placed over the rock layer. The purpose of the sandy loam is to avoid undue soil compaction so that the pore spaces are maintained, and soil air and moisture can move freely. The entire mound area is covered with a 6 -inch layer of 1 topsoil, upon which a grass cover should be established as soon as possible. 1 u 1 What Mounds Look Like PERFORATED LATERALS SANDY LOAM SOIL �, ; +•''•_ ~sw .'R..�, +!''�N�' ••• LAYER OF GEOTEXTILE �' .. ;�' • .f :' FABRIC OR 4 INCHES OF !,;: ✓.� / i �' HAY COVERED BY .; BUILDING PAPER fez PIPE FROM PUMP OR 2 CLEAN WOCK * �• DIVERSION FOR SURFACE WATER 6" TOPSOIL . tea• ? sc = - • / i ; 11/ MA 4 .� SL S LEAN FILL BSOD i6• B ARRIERR lq - - ER Figure E -1 to �1� LAYER OF GEOTEXTILE FABRIC GRASS COVER- - CLEAN SAND FILL - - --, MAXIMUM SLOPE 3 TO i _� r LOAMY SAND CAP r-PERFORATED LATERAL �PSOIL L PLOWED OR 3 /4 TO 2'/2 DISKED SURFACE — F SUBSOIL CROSS SECTION A — A PIPE FROM PUMPING CHAMBER W � -T 7 J r Y O PERFORATED 1 LATERALS � 1 k BED AREA. A NN � W W 1 z z ' 1 i , INCHES -- C vF'v INCHES DIKE _, 1 0 FEET — DIKE —, MAX. TOTAL WIDTH PLAN VIEW Figure E -2 The design material presented in this section suggests a possible approach. It is intended to deal primarily with mounds for single - family residences, or daily sewage flow rates of no more than 1200 gallons. A flow of 1200 gallons per day can be treated with a rock bed 10 feet wide by 100 feet long in a properly constructed mound or berm. However, the proper hydraulic operation of a mound depends on lateral as well as vertical seepage. The design criteria of this section cannot be simply multiplied by a scale factor and expected to properly treat larger flows. The hydraulics of lateral and vertical movement o the clean sand layer and Design Criteria Based on Analysis F 1 1 1 1 IT L X0 . ............ . . ............. UNIVERSITY I s . a OF MINNESOTA 5 IA P , i 1. • AR13ORETUM 5 IA P , i 1. BOARD OF ADJUSTMENTS AND APPEALS MINUTES December 13, 1993 MEMBERS PRESENT: Carol Watson, Willard Johnson and Mark Senn ' STAFF PRESENT: Sharmin Al -Jaff, Planner H, and Steve Kirchman, Building Official. Willard Johnson opened the meeting. I UPDATE ON 93 -9 VARIANCE (PAPKE) - VARIANCE REQUEST TO LOCATE A SEPTIC SYSTEM 75 FEET FROM THE EDGE OF A WETLAND TO SERVE A SINGLE FAMILY RESIDENCE I Al -Jaff and Kirchman presented the staff report update. , The Board members were reminded that this variance is for a wetland setback and not the design of the septic system. Kirchman discussed codes regulating on -site sewage treatment systems, their performance, and staff experience with the many systems in the city. Options to standard systems were also discussed. Kirchman also stated that staff has investigated three failures in the southeast part of the City that involved liquids surfacing at the toe of the downslope dikes. Preliminary indications are that the liquids are a combination of treated effluent and ground water. Surfacing has been attributed to improper landscaping and system overloading. Watson asked if the city monitors the existing systems, and Kirchman stated that a new program has been developed that would allow the city to inspect those systems once every two years. The inspections will begin in spring of 1994. Senn moved to deny Variance #93 -9. Watson seconded the motion. All voted in favor and the motion carried unanimously. A FOUR (4) FOOT SHORELAND SETBACK VARIANCE FOR CONSTRUCTION OF A GARAGE/ROOM ADDITION AT 9119 LAKE RILEY BLVD., JOHN B. AND MARLYN G. GOULETT. The Board of Adjustments and Appeals indicated that staff did not need to present the staff report. Senn moved to approve variance request #93 -10 for a four (4) foot shoreland setback variance. Watson seconded the motion. All voted in favor and the motion carried. Approval of Minutes Watson moved to approve the minutes dated November 22, 1993, ' Johnson seconded the motion. All voted in favor. Johnson closed the public hearing. Johnson moved to adjourn the meeting. Senn seconded the motion. All voted in favor. 1 J ' Date: 11/30/93 I To: Chanhassen City Council From: Jim and Jo Ginther 3131 Dartmouth Drive Chanhassen MN Subject: Proposed Development Boyer's Spinnaker Wharf We are familiar with the Boyer family and their reputation as responsible and quality real estate developers in the Minnetonka area. The entire family lived across the street in our first few years in Sterling Estates. We do have very strong concerns regarding three specific aspects of the proposed development: 1. Changing the zoning from low density R.S.F. to zero lot line PUD medium density 2. The singular access to the project via Dartmouth Drive 3. The proposed 26 boat slip dock Well established R.S.F. zoned neighborhoods are contiguous to the property on both the east and west boundaries. Present home owners bought and developed their homes with the assurance that the undeveloped property was zoned for R.S.F. low density development. It was the applicant himself who developed Sterling Estates to the west with single family homes on large lots. Now, the same developer is proposing to have the zoning changed, to completely change the character of the entire north shore Minnewashta neighborhood and create a severe negative traffic impact on the existing Sterling Estates area and to the lake itself. Why have zoning regulations if every time a developer comes along they simply petition to change the classification, and the character and integrity of the area is completely changed? Is this fair to those neighbors who invested in homes and paid taxes with the confidence that zoning was in place to protect their investment, their lifestyle and in this case their safety? If zoning means nothing, then the integrity and very value of having a Planning Commission and City Council to protect the existing residents of the community is questionable. The congestion that will occur from an additional 52 cars (two per household) making multiple trips in and out of the subdivision daily from one access will have a significant negative impact on the residents of Arbor and Dartmouth Drives. Currently, there is often a two-three minute delay in exiting Arbor Drive onto Highway 7 during morning hours. The addition of potentially another 50 cars using the same street to access Highway 7 definitely will cause unreasonable delays. Also, exiting Highway 7 from the east, onto Arbor, is already a very dangerous left turn in front of high speed oncoming traffic due to high density and poor visibility. l Page 2 ' Additionally, the safety of Sterling Estate residents will be threatened by such a congested access route since the subdivision does not have sidewalks, and both Arbor and Dartmouth Drives are ' commonly used by residents, children and guests for foot traffic. Since Highway 7 borders Sterling Estates to the north and Lake Minnewashta to the south, there are no other alternatives for pedestrian traffic. The only reasonable solution is to add a second access to the east border of the property ' onto Washta Bay Road (this option was in the developer's original plans) or create a frontage road that would access the property from the north. Our third concern regards the excessive amount of boats contemplated to be docked in front of ' the proposed subdivision and added to the boat traffic on Lake Minnewashta. In comparison to the public park directly across the bay that has 400 acres, two public boat landings and a mile ' of shoreline which is limited to 35 boats, the request to add 26 boats is totally unreasonable. The DNB's incorrect interpretation of the channel as lake shoreline and the developer's resulting ' leverage of that faulty definition to request a boat slip for each. residence in a cluster home development where in reality, 18 of the 26 homes are truly off the lake, is not consistent with any reasonable standards of boat regulation. In other Lake Minnewashta developments in the ' past there has been far more conservative regulation of added boat congestion. A workable solution would be to limit the number of boat slips to the same number of ' cluster homes that actually front on the lake. In addition, one or two boat racks to store small sail boats and canoes, accessed through the channel, would be consistent with the location of the off -lake homes and a reasonable addition to lake boat traffic. ' We have been Lake Minnewashta residents for over twenty years. We have developed and maintained an expensive home on the lake and have paid well over $100,000 in real estate taxes ' for this property with the confidence that protective zoning was established. We are not opposed to progress or development that meets a community need and enhances a very special natural resource. We do believe that it is the responsibility of Chanhassen, Carver County and Minnesota State officials to be conscious of the concerns of those Lake Minnewashta residents who currently live their daily lives there, who raise their family's there and who will be impacted most by the proposed development. We have worked hard to maintain the special ' natural qualities of the lake and its surrounding area and we request that our concerns receive your strongest consideration. I