(A) Best Management Practices encouraged and Stormwater Pollution Prevention Plan required.
(1) Best Management Practices (BMPs) encouraged. Whenever possible, existing natural drainageways, wetlands and vegetated soil surfaces must be used to convey, store, filter and retain stormwater runoff before discharge to public waters.
(a) Development must be planned and conducted in a manner that will minimize the extent of disturbed areas, runoff velocities, erosion potential and reduce and delay runoff volumes. Disturbed areas must be stabilized and protected as soon as possible and facilities or methods used to retain sediment on the site.
(b) When development density, topographic features and soil and vegetation conditions are not sufficient to adequately handle stormwater runoff using natural features and vegetation, various types of constructed facilities such as diversions, settling basins, skimming devices, dikes, waterways and ponds may be used. Preference must be given to designs using surface drainage, vegetation and infiltration rather than buried pipes and human-made materials and facilities.
(2) Stormwater Pollution Prevention Plan.
(a) A Stormwater Pollution Prevention Plan (SWPPP) shall be required to all proposed land development activity, unless otherwise exempted in this ordinance that meets any or all of the following:
1. Any land development activity that may ultimately result in the addition of one acre or greater of impervious surfaces, including smaller individual sites that are part of a common plan of development that may be constructed at different times;
2. A subdivision plat;
3. The construction of any new public or private road; and/or
4. Any land development activity, regardless of size, that the county determines is likely to cause an adverse impact to an environmentally sensitive area or other property.
(b) A SWPPP shall be required providing the measures to be taken to control or manage runoff and erosion from such land disturbance both during construction and after final stabilization of the site. No building permit, subdivision approval or permit to allow land-disturbing activities shall be issued until approval of this SWPPP. All SWPPPs shall be consistent with National Pollutant Discharge Elimination System (NPDES) permit requirements, and the filing or approval requirements of other regulatory bodies.
(B) Erosion and sediment control permit required. An Erosion and Sediment Control (ESC) permit, including an Erosion and Sediment Control Plan shall be required to all proposed land-disturbing activity, unless otherwise exempted in this ordinance that meets any or all of the following:
(1) Disturbs a total land surface area of 3,000 square feet or more;
(2) Involves excavation or filling, or a combination of excavation and filling, in excess of 400 cubic yards of material;
(3) Involves the laying, repairing, replacing or enlarging of an underground utility, pipe or other facility, or the disturbance of road ditch, grass swale or other open channel for a distance of 300 feet or more; or
(4) Is a land-disturbing activity, regardless of size, that the county determines is likely to cause an adverse impact to an environmentally sensitive area or other property, or may violate any other erosion and sediment control standard set forth in this ordinance.
(C) Exemptions. The following activities shall be exempt from all of the requirements of this ordinance:
(1) Emergency work to protect life, limb or property; and
(2) Routine agricultural activity. Tilling, planting, harvesting and associated activities. Other agricultural activities are not exempt and including activities such as feedlots, storage sheds.
(D) Stormwater and erosion and sediment control specifications.
(1) Stormwater Pollution Prevention Plan requirements. The minimum requirements of the SWPPP shall be consistent with the most recent version of the NPDES permit requirements.
(2) Erosion and Sediment Control Plan requirements. The minimum requirements of the ESC Plan shall be consistent with the most recent version of the NPDES permit requirements.
(E) Stormwater and erosion and sediment control performance standards. Stormwater management performance standards.
(1) Volume control for water quantity. All stormwater facilities shall be designed, installed and maintained to effectively accomplish the following:
(a) Maintain predevelopment peak runoff rates for the one-year and two-year, 24-hour storm events;
(b) Maintain predevelopment peak runoff rates for the ten-year, 24-hour storm event. At a minimum, the storm sewer conveyance system shall be designed for this storm event. Low areas must have an acceptable overland drainage route with the proper transfer capacity when the storm event is exceeded;
(c) Provide a stable emergency overflow to safely pass the 100-year, 24-hour storm event or the 100-year ten-day snowmelt, whichever is greater;
(d) Discharges must have a stable outlet capable of carrying designed flow at a non-erosive velocity. Outlet design must consider flow capacity and flow duration. This requirement applies to both the site outlet and the ultimate outlet to stormwater conveyance or waterbody;
(e) The project shall use existing natural drainageways and vegetated soil surfaces to convey, treat, filter and retain stormwater runoff before discharge into public waters or a stormwater conveyance system. The applicant shall limit the impervious surface of the developed site or subdivision by incorporating design considerations identified in the Minnesota Stormwater Manual such as narrowing street widths, reducing parking lot space, reducing setbacks and driveways, maximizing open space while incorporating smaller lot sizes to conserve natural areas to help reduce the amount of stormwater runoff generated at the site; and
(f) Runoff from rooftops, driveways and other impervious areas shall be directed to pervious surfaces, where feasible, or unless the applicant can demonstrate the practice is likely to result in nuisance flooding and/or groundwater contamination.
(2) Infiltration for volume reduction. The following requirements must be met.
(a) Infiltration volumes and facility sizes shall be designed using the procedures in Chapter 12 of the Minnesota Stormwater Manual.
(b) Design and placement of infiltration BMPs shall be done in accordance with the State Department of Health guidance called “Evaluating Proposed Stormwater Infiltration Projects in Vulnerable Wellhead Protection Areas”.
(3) Protection of surface waters. Waterbodies shall be protected from runoff generated during construction and after completion of the development in accordance with state statutes and the NPDES permit. Runoff shall not be discharged directly into surface waters without appropriate quantity and quality runoff control.
(4) Buffers.
(a) Buffers are areas of vegetation located adjacent to receiving waters to protect water quality. Buffers help minimize runoff of sediment, debris, nutrients and pesticides into receiving waters by providing an area of undisturbed vegetation in order to trap sediment and debris from adjacent land areas.
(b) Buffers for water quality protection shall commence at the “ordinary high water mark”, or at the delineated boundary of the waterbody.
(c) The widths are established by the slope of land between the activity and the water body as follows:
(5) Slope of land between activity and water body.
Recommended Width of Filter Strip | |
Slope | Distance* |
0 to 10% | 50 feet |
11 to 20% | 51 to 70 feet |
21 to 40% | 71 to 110 feet |
41 to 70% | 111 to 150 feet |
*For roads, distance is measured from the edge of soil disturbance. For fills, distance is measured from the bottom of the fill slope, filter strip width increases approximately two feet for each percent increase in slope above 10%. For example, the filter strip recommendation for a range in slope values from 11 to 20% is 51 to 70 feet. If the slope is 18%, then the filter strip width is 66 feet. | |
(a) The applicant shall maintain the buffer for the first year after completion of the project.
(b) Where land-disturbing construction activity occurs within a buffer area, and where no impervious surface is present, adequate approved native vegetative cover of 70% or greater shall be established and maintained. The native vegetative cover shall be sufficient to provide for bank stability from upslope overland flow areas under sheet flow conditions. Non-vegetative materials, such as rock riprap, may be employed on the bank as necessary to prevent erosion, such as on steep slopes or where high velocity flows occur.
(c) BMPs such as filter strips, swales or wet detention basins, designed to control pollutants from nonpoint pollution sources may be located in the buffer area.
(d) For special waters, impaired waters and wetlands in areas identified by the county as exceptional buffers shall be a minimum of 100 feet.
(6) Special, impaired and/or TMDL water requirements. All projects to special, impaired and/ or TMDL waters must meet the minimum requirements of the NPDES permit to discharge stormwater associated with construction activity.
(7) Erosion and sediment control performance standards.
(a) Construction activity requirements for erosion and sediment control are provided in the NPDES permit. They include stormwater pollution prevention plans, erosion prevention practices, sediment control practices, dewatering and basin draining, and final stabilization.
(b) In addition, streets shall be cleaned and swept within 24-hours whenever tracking of sediment of occurs and before sites are left idle for weekends and holidays.
(F) Pollution prevention. In addition to the following the applicant will comply with NPDES permit for pollution prevention management measures.
(1) Illegal disposal.
(a) No person shall throw, deposit, place, leave, maintain or keep or permit to be thrown, placed, left, maintained or kept, any refuse, rubbish, garbage or any other discarded or abandoned objects, articles or accumulations, in or upon any street, alley, sidewalk, storm drain, inlet, catch basin conduit or drainage structure, business place or upon any public or private plot of land in county, so that the same might be or become a pollutant, except in containers, recycling bags or other lawfully established waste disposal facility.
(b) No person shall intentionally dispose of grass, leaves, dirt or other landscape debris into a water resource buffer, street, road, alley, catch basin, culvert, curb, gutter, inlet, ditch, natural watercourse, flood control channel, canal, storm drain or any fabricated natural conveyance.
(2) Illicit discharges and connections.
(a) No person shall cause any illicit discharge to enter the public stormwater system unless such discharge:
1. Consists of non-stormwater that is authorized by an NPDES point source permit obtained from the MPCA; and
2. Is associated with firefighting activities.
(b) No person shall use any illicit connection to intentionally convey non-stormwater to county stormwater system.
(3) Good housekeeping provisions. Any owner or occupant of property within the county shall comply with the following good housekeeping requirements.
(a) No person shall leave, deposit, discharge, dump or otherwise expose any chemical or septic waste in an area where discharge to streets or storm drain system may occur. This section shall apply to both actual and potential discharges. For pools, water should be allowed to sit seven days to allow for chlorine to evaporate before discharge. If fungicides have been used, water must be tested and approved for discharge to the wastewater treatment plant.
(b) Runoff of water from residential property shall be minimized to the maximum extent practicable.
(c) Runoff of water from the washing down of paved areas in commercial or industrial property is prohibited unless necessary for health or safety purposes and not in violation of any other provisions in county codes.
(4) Storage of materials, machinery and equipment.
(a) Objects, such as motor vehicle parts, containing grease, oil or other hazardous substances, and unsealed receptacles containing hazardous materials, shall not be stored in areas susceptible to runoff.
(b) Any machinery or equipment that is to be repaired or maintained in areas susceptible to runoff shall be placed in a confined area to contain leaks, spills or discharges.
(5) Removal of debris and residue. Debris and residue shall be removed, as noted below.
(a) All motor vehicle parking lots shall be swept, at a minimum of twice a year to remove debris. Such debris shall be collected and properly disposed.
(b) Fuel and chemical residue or other types of potentially harmful material, such as animal waste, garbage or batteries, which is located in an area susceptible to runoff, shall be removed as soon as possible and disposed of properly. Household hazardous waste may be disposed of through county collection program or at any other appropriate disposal site and shall not be place in a trash container.
(G) Inspections and maintenance.
(1) Inspections and enforcement. The applicant is responsible for inspections and record keeping in accordance with the NPDES permit requirements. The County Engineer, or a consulting engineer assigned by the County Engineer shall conduct inspections, at an applicant’s expense, on a regular basis to ensure that both stormwater and erosion and sediment control measures are properly installed and maintained prior to construction, during construction, and at the completion of the project. Mandatory inspections are required as follows:
(a) Before any land-disturbing activity begins;
(b) At the completion of the project; and
(c) Prior to the release of financial securities.
(2) Stop work order. In cases where cooperation is withheld, construction stop work orders shall be issued by the county, until stormwater and erosion and sediment control measures meet the requirements of this ordinance. An inspection must follow before work can commence. Expenses incurred by the county will be paid by the developer.
(3) Construction stop order. The county may issue construction stop orders until stormwater management measures meet specifications. A second stormwater management inspection must then be scheduled and passed before the final inspection will be done.
(4) Perimeter breach. If stormwater and/or erosion and sediment control management measures malfunction and breach the perimeter of the site, enter streets, other public areas, or waterbodies, the applicant shall immediately develop a cleanup and restoration plan, obtain the right-of-way from the adjoining property owner, and implement the cleanup and restoration plan within 48 hours of obtaining permission, if in the discretion of the county, the applicant does not repair the damage caused by the stormwater runoff the county can do the remedial work required and charge the cost to the applicant.
(5) Actions to ensure compliance. The county can take the following action in the event of a failure by applicant to meet the terms of this ordinance:
(a) Withhold inspections or issuance of certificates or approvals;
(b) Revoke any permit issued by the county to the applicant;
(c) Conduct remedial or corrective action on the development site or adjacent site affected by the failure;
(d) Charge applicant for all costs associated with correcting the failure or remediating damage from the failure. If payment is not made within 30 days, payment will be made from the applicant’s financial securities;
(e) Bring other actions against the applicant to recover costs of remediation or meeting the terms of this ordinance; and
(f) Any person, firm or corporation failing to comply with or violating any of these regulation shall be deemed guilty of a misdemeanor and be subject to a fine or imprisonment or both. Each day that a separate violation exists shall constitute a separate offense.
(H) Long-term inspection and maintenance of stormwater facilities.
(1) Private stormwater facilities. No private stormwater facilities may be approved unless a maintenance plan is provided that defines who will conduct the maintenance, the type of maintenance and the maintenance intervals. All private stormwater facilities shall be inspected annually and maintained in proper condition consistent with the performance standards for which they were originally designed.
(a) Facility access. Access to all stormwater facilities must be inspected annually and maintained as necessary. It shall be the responsibility of the applicant to obtain any necessary easements or other property interests to allow access to the facilities for inspection or maintenance for both the responsible party and the county.
(b) Removal of settled materials. All settled materials from ponds, sumps, grit chambers and other devices, including settled solids, shall be removed and properly disposed of.
(c) County inspections. All stormwater facilities within the county shall be inspected by the County Engineer or a consulting engineer assigned by the County Engineer, during construction, during the first year of operation, and at least once every five years thereafter.
(2) Public stormwater facilities.
(a) Acceptance of publicly owned facilities. Before work under the permit is deemed complete, the permittee must submit as-builts and a maintenance plan to the County Engineer demonstrating at the time of final stabilization that the stormwater facilities conform to design specifications. A final inspection shall be required before the county accepts ownership of the stormwater facilities.
(b) Inventory of stormwater facilities. Upon adoption of this ordinance, the county shall inventory and maintain a database for all private and public stormwater facilities within county requiring maintenance to assure compliance with this ordinance. The county shall notify owners of public and private stormwater facilities of the need for conducting maintenance at least every five years, following the completion and public acceptance of the facilities.
(c) Maintenance. The county shall perform maintenance of publicly owned stormwater facilities in accordance with their comprehensive stormwater management plan and other regulatory requirements.
(I) Permit review process, financial procedures and enforcement actions.
(1) Pre-review. The County Engineer shall make a determination regarding the completeness of a permit application within ten days of the receipt of the application and notify the applicant if the application is not complete.
(2) Permit review. The applicant shall not commence any construction activity subject to this ordinance until a permit has been authorized by the County Engineer. A complete review of the permit application shall be done within 14 business days of the receipt of a complete permit application from the applicant. The county will work with the necessary state, county and local agencies to complete the review.
(3) Permit authorization. If the county determines that the application meets the requirements of this ordinance, the county may issue approval which authorizes the project or activity. The approval shall be valid for one year. Approval will typically be in the form of a letter from the County Engineer to the applicant.
(4) Permit denial. If the county determines the application does not meet the requirements of this ordinance, this application must be resubmitted for approval before activity begins. All land use and building permits shall be suspended until the applicant has an authorized permit.
(5) Modification of plans. The applicant must amend the ESC Plan or SWPPP as necessary to include additional requirements such as additional or modified BMPs designed to correct problems identified or address situations whenever:
(a) A change in design, construction, operation, maintenance, weather or seasonal conditions that has a significant effect on the discharge of pollutants to surface waters or underground waters;
(b) Inspections or investigations by site operators, local, state or federal officials indicate the plans are not effective in eliminating or significantly minimizing the discharge of pollutants to surface waters or underground waters or that the discharges are causing water quality standard exceedances; or
(c) The plan is not achieving the general objectives of minimizing pollutants in stormwater discharges associated with construction activity, or the plan is not consistent with the terms and conditions of this permit.
(6) Variance requests. The county may grant a variance on a case-by-case basis. The content of a variance shall be specific, and shall not affect other approved provisions of a permit.
(a) The variance request shall be in writing and include the reason for requesting the variance.
(b) Economic hardship is not sufficient reason for granting a variance.
(c) The county shall respond to the variance request in writing and include the justification for granting or denying the request.
(7) Financial securities. The applicant shall provide security for the performance of the work described and delineated on the approved permit and related remedial work in an amount of $3,000 per gross acre ($6,000 for work done in special or impaired waters as determined by the county) or $1,500 for each single or two-family home, whichever is greater. This amount shall apply to the maximum acreage of soil that will be simultaneously exposed during the project’s construction. The form of the securities shall be one or a combination of the following to be determined by the county.
(a) Cash deposit. The first $3,000 of the financial security for erosion and sediment control shall be by cash deposit to the county.
(b) Securing deposit. Deposit, either with the county, a responsible escrow agent, or trust company, at the option of the county, either:
1. An irrevocable letter of credit or negotiable bonds of the kind approved for securing deposits of public money or other instruments of credit from one or more financial institutions, subject to regulation by the state and federal government wherein the financial institution pledges funds are on deposit and guaranteed for payment;
2. Cash in U.S. currency; or
3. Other forms and securities (e.g., disbursing agreement) as approved by the county.
(c) County free and harmless. This security shall save the county free and harmless from all suits or claims for damages resulting from the negligent grading, removal, placement or storage of rock, sand, gravel, soil or other like material within the county.
(8) Maintaining the financial security. If at anytime during the course of the work this amount falls below 50% of the required deposit, the developer shall make another deposit in the amount necessary to restore the cash deposit to the required amount. If the developer does not bring the financial security back up to the required amount within seven days after notification by the county that the amount has fallen below 50% of the required amount, the county may:
(a) Withhold inspections. Withhold the scheduling of inspections and/or the issuance of a certificate of occupancy.
(b) Revocation of permits. Revoke any permit issued by the county to the applicant for the site in question or any other of the applicant’s sites within the county’s jurisdiction.
(9) Proportional reduction of the financial security. When more than one-third of the applicant’s maximum exposed soil area achieves final stabilization, the county can reduce the total required amount of the financial security by one-third. When more than two-thirds of the applicant’s maximum exposed soil area achieves final stabilization, the county can reduce the total required amount of the financial security to two-thirds of the initial amount. This reduction in financial security will be determined by the county staff.
(10) Action against the financial security. The county may access financial security for remediation actions if any of the conditions listed below exist. The county shall use the security to finance remedial work undertaken by the county, or a remedial work including, but not limited to, staff time and attorney’s fees.
(a) Abandonment. The developer ceases land-disturbing activities and/or filling and abandons the work site prior to completion of the grading plan.
(b) Failure to implement the SWPPP or ESC plan. The developer fails to conform to the grading plan and/or the SWPPP as approved by the county.
(c) Failure to perform. The techniques utilized under the SWPPP fail within one year of installation.
(d) Failure to reimburse county. The developer fails to reimburse the county for corrective action taken.
(11) Returning the financial security. The security deposited with the county for faithful performance of the SWPPP or the ESC Plan and any related remedial work shall be released one full year after the completion of the installation of all stormwater pollution control measures as shown on the SWPPP or ESC Plan.
(12) Emergency action. If circumstances exist such that noncompliance with this ordinance poses an immediate danger to the health, safety and welfare, as determined by the county, the county may take emergency preventative action. The county shall also take every reasonable action possible to contact and direct the applicant to take any necessary action. Any cost to the county may be recovered from the applicant’s financial security.
(13) Notification of failure of the permit. The county shall notify the permit holder of the failure of the permit’s measures.
(a) Initial contact. The initial contact will be to the party or parties listed on the application and/or the SWPPP as contacts. Except during an emergency action, 48 hours after notification by the county or 72 hours after the failure of erosion and sediment control measures, whichever is less, the county at its discretion, may begin corrective work. Such notification should be in writing, but if it is verbal, a written notification should follow as quickly as practical. If after making a good faith effort to notify the responsible party or parties, the county has been unable to establish contact, the county may proceed with corrective work. There are conditions when time is of the essence in controlling erosion. During such a condition, the county may take immediate action, and then notify the applicant as soon as possible.
(b) Erosion off-site. If erosion breaches the perimeter of the site, the applicant shall immediately develop a cleanup and restoration plan, obtain the right-of-entry from the adjoining property owner, and implement the cleanup and restoration plan within 48 hours of obtaining the adjoining property owner’s permission. In no case, unless written approval is received from the county, may more than seven calendar days go by without corrective action being taken.
(c) County may do remedial work. If in the discretion of the county, the permit holder does not repair the damage caused by the erosion, the county may do the remedial work required. When restoration to wetlands and other resources are required, the applicant should be required to work with the appropriate agency to ensure that the work is done properly.
(d) Erosion into streets, wetlands or water bodies. If eroded soils (including tracked soils from construction activities) enter or appear likely to enter streets, wetlands or other water bodies, cleanup and repair shall be immediate. The applicant shall provide all traffic control and flagging required to protect the traveling public during the cleanup operations.
(e) Failure to do corrective work. When an applicant fails to conform to any provision of this policy within the time stipulated, the county may take the following actions:
1. Issue a stop work order, withhold the scheduling of inspections, and/or the issuance of a certificate of occupancy;
2. Revoke any permit issued by the county to the applicant for the site in question or any other of the applicant’s sites with in the county’s jurisdiction;
3. Correct the deficiency or hire a contractor to correct the deficiency;
4. Require reimbursement to the county for all costs incurred in correcting stormwater pollution control deficiencies;
5. If payment is not made within 30 days after costs are incurred by the county, payment will be made from the applicant’s financial securities as described in subsection (I)(7) above; and/or
6. If there is an insufficient financial amount in the applicant’s financial securities as described in subsection (I)(7) above, then the county may assess the remaining amount against the property. As a condition of the permit, the owner shall waive notice of any assessment hearing to be conducted by the county, concur that the benefit to the property exceeds the amount of the proposed assessment, and waive all rights by virtue of M.S. § 429.081, as it may be amended from time to time, to challenge the amount or validity of assessment.
(14) Enforcement. The county shall be responsible enforcing this ordinance and assessing any penalties. Any person, firm or corporation failing to comply with or violating any of these regulations, shall be deemed guilty of a misdemeanor and be subject to a fine or imprisonment or both. All land use and building permits must be suspended until the applicant has corrected the violation. Each day that a separate violation exists shall constitute a separate offense.
(15) Right of entry and inspection. The issuance of a permit constitutes a right-of-entry for the county or its contractor to enter upon the construction site. The applicant shall allow the county and its authorized representatives, upon presentation of credentials to:
(a) Enter upon the permitted site for the purpose of obtaining information, examination of records, conducting investigations or surveys;
(b) Bring such equipment upon the permitted development as is necessary to conduct such surveys and investigations;
(c) Examine and copy any books, papers, records or memoranda pertaining to activities or records required to be kept under the terms and conditions of this permitted site;
(d) Inspect the stormwater pollution control measures;
(e) Sample and monitor any items or activities pertaining to stormwater pollution control measures; and
(f) Correcting deficiencies in stormwater and erosion and sediment control measures.
(16) Abrogation and greater restrictions. It is not intended to repeal, abrogate or impair any existing easements, covenants or deed restrictions; however, where this ordinance imposes greater restrictions, the provisions of this ordinance shall prevail. All other ordinances inconsistent with this ordinance are hereby repealed to the extent of the inconsistency only.
(Ord. 97, passed 7-21-2009)