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7.b i Approving a variance from the bluffline setback for a septic system at 23209 St. Croix TrailMemorandum To: Scandia City Council Copies To: Neil Soltis, City Administrator Brenda Eklund, City Clerk Larry Bloomer, applicant, on behalf of the National Park Service — St. Croix National Scenic Riverway From: Sherri Buss, RLA AICP, Planner Date: August 14, 2018 SUBJECT: MEETING DATE: LOCATION: APPLICANTS ZONING: 60 -DAY PERIOD ITEMS REVIEWED: Reference: National Park Service Variance request for Sewage Treatment System Location Project No.: 16622.008 Routing: National Park Service request for Variance to replace a subsurface septic treatment system at the Magney Quarters August 21, 2018 23209 St. Croix Trail North PID 0703219210002 Scandia, Minnesota National Park Service — St 401 North Hamilton Street St. Croix Falls, Wisconsin Croix National Scenic Riverway 54024 Agriculture — Core (AG C) and St. Croix River Overlay District September 17, 2018 Application, survey, and supplemental information received July 19, 2018 BRIEF DESCRIPTION OF THE REQUEST: The National Park Service (NPS) has submitted a Sewage Treatment System Permit Application to Washington County to replace an existing subsurface septic treatment system (SSTS) at the NPS property at 23209 St. Croix Trail North. The County is willing to approve the An employee owned company promoting affirmative action and equal opportunity 444 Cedar Street, Suite 1500 Saint Paul, MN 55101 651.292.4400 tkda.com Mi TKDA Memorandum To: Scandia City Council Copies To: Neil Soltis, City Administrator Brenda Eklund, City Clerk Larry Bloomer, applicant, on behalf of the National Park Service — St. Croix National Scenic Riverway From: Sherri Buss, RLA AICP, Planner Date: August 14, 2018 SUBJECT: MEETING DATE: LOCATION: APPLICANTS ZONING: 60 -DAY PERIOD ITEMS REVIEWED: Reference: National Park Service Variance request for Sewage Treatment System Location Project No.: 16622.008 Routing: National Park Service request for Variance to replace a subsurface septic treatment system at the Magney Quarters August 21, 2018 23209 St. Croix Trail North PID 0703219210002 Scandia, Minnesota National Park Service — St 401 North Hamilton Street St. Croix Falls, Wisconsin Croix National Scenic Riverway 54024 Agriculture — Core (AG C) and St. Croix River Overlay District September 17, 2018 Application, survey, and supplemental information received July 19, 2018 BRIEF DESCRIPTION OF THE REQUEST: The National Park Service (NPS) has submitted a Sewage Treatment System Permit Application to Washington County to replace an existing subsurface septic treatment system (SSTS) at the NPS property at 23209 St. Croix Trail North. The County is willing to approve the An employee owned company promoting affirmative action and equal opportunity NPS Variance for Sewage Treatment System Scandia City Council Page 2 August 21, 2018 design of the system, but stated that its proposed location requires a variance from the required setback from the bluffline. The City is the zoning authority for granting the variance from the required setback. The parcel area is 21.24 acres in area and it is located in the Agriculture - Core (AG C) District and the St. Croix River Overlay District. BACKGROUND The National Park Service is proposing to replace an existing SSTS with a new system in the same location as elements of the existing system on a parcel located at 23209 St. Croix Trail North. The existing sewage treatment system includes 1 tank at a location along the driveway north of the dwelling, and a cistern on the edge of the bluff. The system served the house prior to the NPS acquisition of the property. The new system will include 2 tanks to process the waste, and liquids will then be pumped to a new drainfield. All elements of the new system will be located along the driveway in the location shown on the site plan. The parcel is located on the bluffs adjacent to the St. Croix River and within the St. Croix Riverway Overlay Zoning District. The required sewage treatment system setbacks in the Riverway District are 150 feet from the OHWL and 40 feet from the bluffline. The existing cistern is located within a few feet of the bluffline and is therefore a "substandard structure" as defined in the St. Croix Riverway Ordinance: "Substandard structure means any structure established before the effective date of the St. Croix Riverway Ordinance which is permitted within a particular zoning district but does not meet the structure setbacks or other dimensional standards of the Ordinance." The St. Croix Riverway Ordinance requires that `7f a substandard structure needs replacement due to destruction, deterioration, or obsolescence, such replacement shall comply with the dimensional standards of the ordinance."The applicant is requesting a variance to permit placing the new system tanks in approximately the same location as the existing cistern and the new drainfield in a location to the north. The proposed locations of the new system would not meet the setback requirement from the bluff line. The City may grant a variance from these ordnance standards if there is no other location where the system can meet the setback requirements and if the request meets the "practical difficulties" criteria in the City's Development Code. The applicant has worked with a septic system designer and Washington County to design a system that meets the County SSTS Ordinance requirements. The application states that the designer's analysis found that there is no location on the property that would allow installation of the proposed system on suitable soils where it would meet the bluff setback requirement. The proposed location meets the required setback from the Ordinary High Water Level of the St. Croix River and the other setback requirements that apply to the proposed sewage treatment system. EVALUATION OF VARIANCE REQUEST Comprehensive Plan and St. Croix Riverway Ordinance The Comprehensive Plan established the Agriculture - Core (AG C) District to protect and encourage long-term agriculture. Residential development is permitted as a secondary use in the District. The Comprehensive Plan also supports protection of the natural and scenic resources of the St. Croix River Corridor through the application of the St. Croix Riverway I NPS Variance for Sewage Treatment System Scandia City Council Page 3 August 21, 2018 District ordinance and its standards as an overlay district in portions of the AG C district that are within the Riverway District. Most of the NPS parcel is located on the bluffs adjacent to the St. Croix River. The existing SSTS area includes soils that can support the proposed system. There is no area on the site where the system could be located on suitable soils that would also meet the bluff setback requirement. The proposed location supports the goals of the St. Croix Riverway Ordinance and Comprehensive Plan goals for the Riverway as follows: • The proposed SSTS will be no closer to the river than the existing system, and will eliminate the existing cistern on the edge of the bluffs which does not meet current standards for SSTS design. The new SSTS will comply with the County's SSTS Ordinance. • The location will minimize new impacts to the bluffs and vegetation. • The location will meet the setback requirement from the OHWL of the St. Croix River and other structure setback requirements. Development Code Requirements: Lot Size and Setbacks The NPS parcel is 21.24 acres in size and meets the minimum 2.5 -acre lot size in the St. Croix River District. Setback Requirements and Proposed Setbacks for SSTS Feature Required Setback Proposed Setback OHWL of St. Croix River 150' Approximately 500' Bluff line 40' 0-5' Water supply wells 50' sewage tanks; 100' soil treatment area Approximately 200' Occupied buildings 10' sewage tanks; 20' soil treatment area Approximately 200' Side property line 20' Approximately 600' Rear property line 50' Approximate) 250' The proposed SSTS requires a variance from the required setback from the bluff line and meets the other setback requirements. Accessory Structures The application does not propose new accessory structures. Lot Coverage The St. Croix River Overlay District permits up to 20% lot coverage. The Planner calculated that the existing lot coverage by impervious surfaces is approximately 1 % of the parcel. The parcel coverage will continue to be approximately 1 % after construction of the new SSTS. The proposed structure replacement meets the impervious cover requirement of the ordinance. 7 NPS Variance for Sewage Treatment System Scandia City Council Page 4 August 21, 2018 Building Height and Color The application does not propose new buildings. Driveway Access The existing driveway will remain and no new access is proposed. Wastewater Treatment and Well The existing SSTS will be removed and replaced by the new system. The new system meets the required setback from the well on the parcel. Impacts to Slopes, Vegetation, and Engineer Comments regarding Grading and Land Alteration The new SSTS is proposed to be located in approximately the same area as the existing system. The Planner provided a copy of the application to the City Engineer for review. He provided the following comments: • The applicant shall obtain a Grading/Land Alteration Permit from the City, and the Engineer shall review the drainage and upland slopes to see if drainage can be diverted temporarily during construction while final restoration is completed and vegetation is established. • The applicant shall have best management practices for erosion and sediment control installed prior to any excavation work. The St. Croix Riverway Ordinance does not require a vegetative cutting permit to constructed a permitted septic system, provided the existing quality, character, density, and canopy is maintained as viewed from the river. The proposed SSTS will replace an existing system in the same location, and therefore should not impact the existing vegetative canopy or views from the St. Croix River. DNR Comments The Planner sent the application to the DNR for review. The DNR's Area Hydrologist provided the following comment on August 7: "Thanks for the opportunity to comment on this variance request by the National Park Service to replace the existing septic system, which does not meet the 40 foot bluff setback at this site in Scandia. A quick look at the topography of the lot (below) shows that this site is mostly bluff and that there are limited for placing a septic system here. DNR has no comment on this variance request in the Lower St. Croix Riverway. Watershed District Comments The Planner sent the application to the Carnelian -Marine -St. Croix Watershed District (CMSCWD) for comments. The CMSCWD Administrator provided the following comment on August 7: "Like the DNR the Watershed District acknowledges the difficult terrain of this site and 7 NPS Variance for Sewage Treatment System Scandia City Council Page 5 August 21, 2018 the lack of suitable area outside of the bluff setback for a replacement septic system. We have no comment on the variance." Landscape Plan No landscape plan is required. CRITERIA FOR VARIANCES AND FINDINGS Chapter 1, Section 6.0 of the Development Code and the Lower St. Croix River Bluffland and Shoreland Management Ordinance include the criteria and required process for considering variance requests. Variances may only be granted when the terms of the variance are consistent with the Comprehensive Plan and in harmony with the general purpose and intent of the development code. The other variance criteria in the Development Code include: 1. The applicant proposes to use the property in a reasonable manner not permitted by the Development Code. 2. The plight of the landowner is due to circumstances unique to the property not created by the landowner. 3. The variance, if granted, will not alter the essential character of the locality. 4. Economic conditions alone shall not constitute practical difficulties. 5. 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, or increase the danger of fire, or endanger the public safety, or substantially diminish or impair property values within the neighborhood. 6. The required variance is the minimum action required to eliminate the practical difficulty. 7. Practical difficulties include, but are not limited to, inadequate access to direct sunlight for solar energy systems. Applicant's Rationale for the Variance The application includes a practical difficulties statement for the variance request that included the following: • There is no location on the parcel that has suitable soils for a septic system that also meets the bluff setback requirement. • The proposed system will replace the existing system and the location will not impact steep slopes, bluffs, vegetation, or views from the St. Croix River. Variance Request and Findings The following bullets include the Planner's findings related to the National Park Service's request for a variance, based on the statutory criteria and ordinance criteria for granting a variance. Each of the criteria is shown in italics: • Variances shall only be permitted when they are in harmony with the general purposes and intent of the official control. 7 NPS Variance for Sewage Treatment System Scandia City Council Page 6 August 21, 2018 The Comprehensive Plan supports protection of the St. Croix River and application of City's Development Code and Riverway Ordinance standards to support the Riverway protection goals. The Lower St. Croix River Ordinance requires that replacement of substandard structures occur in locations that meet setback requirements in order to protect the Riverway and bring properties into compliance with the dimensional standards of the ordinance when they are replaced. The National Park Service has submitted information that there is no location on the parcel where the proposed septic system can be located on suitable soils and meet the required setback from the bluffline. The NPS has included several elements in the design of the septic system to meet the goals and intent of the St. Croix River District: • Placing the proposed septic system no closer to the bluff than the existing structures, eliminating the existing cistern near the bluff, and in a location that meets all of the other setback requirements of the Zoning Ordinance and County SSTS Ordinance. • Placing the septic system on a relatively flat area of the site that outside the areas of steep slopes and bluffs on the parcel. • Placing the septic system in the existing location to avoid impacts to vegetation and views from the St. Croix River. • Replacing the cistern with a new septic system that conforms to the County's SSTS ordinance standards for system design. The proposed variance is in harmony with the general purposes and intent of the official controls based on the finding that there is no location on the parcel where the septic system could be located on suitable soils and meet the bluff setback requirement; the proposed location will remove the existing cistern near the bluff that does not comply with current SSTS design standards; the proposed location will minimize potential impacts to slopes, vegetation and views from the river; and the proposed location complies with the other dimensional requirements of the applicable ordinances and the intent of the official controls. • The property owner proposes to use the property in a reasonable manner under the conditions allowed by official control(s). Septic systems are required for residential uses in the St. Croix Riverway District and Agriculture Core District and are a reasonable use. • The practical difficulties are not caused by the landowner, and are unique to the property. The practical difficulties are unique to the property, and include the location of bluffs on most of the area of the parcel and limited areas of soils suitable for an SSTS which do not allow the septic system to be located in a place that would meet the bluff setback requirement of the St. Croix Riverway Ordinance. • The variance would not alter the essential character of the area. MI NPS Variance for Sewage Treatment System Scandia City Council Page 7 August 21, 2018 The variance would not alter the character of the area. The new SSTS will not be visible from adjacent properties, and the placement of the new system in the same location as the existing system will preserve the existing vegetation on the parcel that screens views from the St. Croix River. • Economic conditions alone shall not constitute practical difficulties. The practical difficulties are not related to economic conditions alone, but are caused by the location of bluffs throughout the parcel and the limited locations of soils on the site that can support the SSTS. • 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, or increase the danger of fire, or endanger the public safety, or substantially diminish or impair property values within the neighborhood. The replacement of the septic system will not impair the supply of light or air to adjacent properties or increase congestion, endanger the public, or substantially diminish or impair property values in the neighborhood. • The requested variance is the minimum action required to eliminate the practical difficulty. Granting the requested variance is the minimum action required to eliminate the practical difficulty and meet the Riverway Ordinance and Development Code requirements. The location of the new SSTS in the same location as the existing tank where it meets the other dimensional requirements of the ordinance will minimize the variance required and minimize impacts to the steep slopes, bluffs, vegetation, and views from the river. • Practical difficulties include, but are not limited to, inadequate access to direct sunlight for solar energy systems. The variance is not related to a need for direct sunlight for solar energy systems. PLANNING COMMISSION PUBLIC HEARING AND RECOMMENDATIONS The Planning Commission held a public hearing on the variance request at their meeting on August 7. The Commission received no verbal comments and received the DNR and CMSCWD written comments concerning the variance request. Commissioners expressed concerns about the location of the proposed system close to the bluff line. They discussed options to require that the system be located farther from the bluff and within the area of the driveway. However, this location would not provide the required separation from the existing well. The Commission recommended that the variance be approved requiring the NPS to location the system the maximum feasible distance and a minimum of 5 feet from the bluffline. I NPS Variance for Sewage Treatment System Scandia City Council Page 8 August 21, 2018 ACTION REQUESTED: The City Council can take the following actions for the request: 1. Approval 2. Approval with conditions 3. Denial with findings 4. Table the request PLANNING COMMISSION RECOMMENDATIONS: The Planning Commission recommends that the City Council approve a variance to permit the replacement of the existing subsurface septic treatment system on the parcel at 23209 St. Croix Trail North with a new SSTS at the maximum feasible distance and a minimum of five feet from the bluff line on the parcel. The Planner recommends the following conditions for the variance: 1. The new structure shall be located and constructed as shown on the site plan and septic system report submitted to the City on July 13, 2018. 2. The applicant shall obtain an approved septic system permit from Washington County, and submit a copy of the permit to the City. 3. The applicant shall obtain a Grading/Land Alteration Permit from the City if the project will excavate, add, or remove ten (10) cubic yards or more of material or disturb six hundred (600) square feet or more. 4. Engineer shall review the drainage and upland slopes to see if drainage can be diverted temporarily during construction while final restoration is completed and vegetation is established. 5. The applicant shall have best management practices for erosion and sediment control installed prior to any excavation work. 6. The applicants shall protect vegetation over six (6) inches in diameter to the extent possible. 7. Site work shall comply with the regulations of the Carnelian -Marine St. Croix Watershed District, and the applicants shall obtain any required District permits. 8. The applicants shall pay all fees and escrows associated with the variance application. I Current system if tank and cistern indicated by the circles Proposed are 2 new tanks located 50' from the well and a forced main to an infiltration bed.