Stormwater Maintenance Plan. for: Riverton City Public Works Facility South 4150 West Riverton, Utah, 84065

Transcription

1 Stormwater Maintenance Plan for: Riverton City Public Works Facility South 4150 West Riverton, Utah, 84065

2 CONTENTS SECTION 1: PURPOSE AND RESPONSIBLITY SECTION 2: POLLUTANT SOURCES SECTION 3: DESCRIPTION OF SITE SYSTEMS, OPERATIONS AND POLLUTION CONTROLS SECTION 4: TRAINING SECTION 5: RECORDKEEPING SECTION 6 APPENDICES SECTION 1: PURPOSE AND RESPONSIBILTY As required by the Clean Water Act and associated local regulations, including Riverton City s Municipal Separate Storm Sewer System (MS4) Permit, Riverton City properties are required to build and maintain systems to minimize contaminates in runoff and litter that pollute waters of the State. The purpose of this Stormwater Maintenance Plan (SMP) is to manage municipal operations at the 4150 West Public Works Facility in order to minimize pollutants in both stormwater and non-stormwater runoff which ultimately drains to Midas Creek and the Jordan River. This SMP is also designed to minimize litter from blowing off of the site. This SMP describes the systems, operations and the minimum standard operating procedures (SOPs) necessary to accomplish these purposes. Any other activities or site operations at this facility that might contaminate water entering the City s stormwater system must be prohibited unless SOPs are written to manage those activities or operations, and this SMP is amended to include those SOPs.

3 SECTION 2: POLLUTANT SOURCES Pollutant Sources Se di m en t Nu trie nts He av y Me tal s ph (ac ids an d ba se s) Pe sti cid es & He rbi cid es Oil & Gr ea se Ba cte ria & Vir us es Tr as h, De bri s, So lid s Ot he r tox ic Ch em ica ls Notes Se di m en t Parking and other Paved Areas and Pavement Maintenance Operations Landscaping Maintenance Operations Waste Management Operations Stormwater System and Maintenance Operations Building Utility Systems Spills Salt Operations Vehicle and Machinery Maintenance Operations Equipment Storage Vehicle and Machinery Cleaning Operations

4 Fueling Operations Street Maintenance Staging Operations Vacuum and Street Sweeping Truck Staging Operations Inventory Storage SECTION 3: DESCRIPTION OF SYSTEMS, OPERATIONS AND POLLUTION CONTROLS This section describes how the facility is designed to control the pollutant sources listed in Section 2, and how operations are managed to reduce the impact this site has on the environment. The operations described in this section are generally exposed to weather and, if managed improperly, can impact the environment. This SMP does not describe the operations that generally occur indoors where pollutants are contained. City staff should use good judgment and conduct their operations appropriately, doing as much as possible indoors and properly managing operations that must be performed outdoors. The drawings of this facility are included in Appendix A. The SOPs for the following operations exposed to weather are filed in Appendix B. Parking and Other Impervious Areas and associated Maintenance Operations The yard area is primarily asphalt, which drains to concrete waterways and stormwater inlets on the east side of this site. Runoff also drains from sidewalk, and other impervious landscapes. Sediment, fluids, and debris that collect on yard pavements, and other impervious areas and how they are dealt with can be a significant source of pollution. The parking and other paved areas must be maintained regularly to minimize the accumulation of pollutants before they can be washed into the stormwater system. Maintenance involves regular sweeping, but it can also involve pavement washing when necessary. The Sweeping and the Pavement Washing SOPs are used to manage the pollutants associated with pavements. Landscape Maintenance Operations Twenty percent of this property is landscaped and is primarily rock mulch, shrubbery, and trees around the perimeter and frontage of the site except for a turf park-strip. During the landscaping maintenance operations, organic materials, herbicides, pesticides, and fertilizers, can be left behind or improperly applied. These pollutants will be carried by

5 runoff if they are not picked up as part of the regular maintenance operation. The Landscaping Maintenance SOP is used to manage the pollutants associated with this operation. Waste Management Operations The Public Works Facility has an 8-feet-tall perimeter fence, a 6-yard dumpster, and trash receptacles with lids. When maintained these controls will reduce the weather exposure to waste materials minimizing the potential for pollutants that can be carried by runoff or wind. Good waste management systems, if managed improperly, can end up being the source of the very pollution that they were intended to control. This pollution source is also controlled by detailed SOPs, a water quality device, and a retention pond(see site map). Inspecting and maintaining the dumpster and trash receptacle devices, are essential to an effective waste management operation. The General Waste Management SOP is used to manage the pollutants associated with this operation. Stormwater System and Maintenance Operations The stormwater system consists of concrete waterways that collect the majority of runoff from the paved area. The length of the waterways allows time for the containment of spills before pollutants reach the inlets. Stormwater inlets at the east side of the property direct all runoff through a stormwater treatment unit which then discharges into an open detention pond which, includes a water quality capture volume (WQCV). The detention pond manages runoff for a 10-year storm event and includes a surface route the pond. The pond s the WQCV holds 18 percent of the total volume, facilitating infiltration and evaporation, capturing low flow pollutants, and recharging groundwater. The roof drainage system connects to six individual sumps draining 16,500 square feet of the roof area also recharging the groundwater with clean runoff. These sumps and the WQCV help to preserve some of the predevelopment hydrology of this property. The stormwater treatment unit is designed to capture floating material and heavier sediment particles, but does not trap suspended or dissolved pollutants. The WQCV provides secondary treatment, trapping some of the pollutants missed by the stormwater treatment unit. However, both systems will not capture all contaminates because large storm event flows will bypass through an overflow. The stormwater system must be maintained regularly to remove the accumulated pollutants before they will be flushed through the system during the high-flow events. Effort must be made to reduce pollutants that collect in the WQCV volume of the pond to minimize the contamination of the soils and the increase of maintenance cost. The Stormwater System Maintenance of this site is incorporated into the Sweeping and Stormwater System Maintenance SOP schedule. Building Utility Systems This property has an outside utility area located at ground level that will drain to the pavement. The heating and air conditioner unit is a York 2J300N32S2VZZ10010B. The

6 MSDS sheet for R410A is provided in the appendix. This pollutant source can be appropriately managed by the Spill Containment and Cleanup SOP and regular site inspection filed in Appendix C. Spill Response Operations Insufficient response, inadequate containment materials and improper spill cleanup methods will result in pollutants in our waterways. Once the pollutants reach the storm drain system, or even the pond, they are difficult and expensive to remove. The Public Works Facility is equipped with spill containment kits located at key locations. The yard area is also designed with waterways rather than inlets to allow for more time to respond and contain fluid spills. The Spill Containment and Cleanup SOP will facilitate a quick and effective response. A water quality device and the retention pond(see site map) will provide redundant traps and containment points. Snow Removal and Deicing Operations Salt is a vital to ensuring a safe transportation system. However, the salt and pre-wetting operations should be properly managed to minimize unnecessary salt impact. This site is equipped with a salt barn. The loading area is exposed to the weather but it is also a brine basin which drains to a tank. The brine is pumped to trucks minimizing unnecessary waste and maximizing the effectiveness of the snow removal and de-icing operations. The Snow Removal and De-icing SOP is used to manage this operation and to maximize the effectiveness of salt usage. Vehicle and Machinery Maintenance Operations Vehicle and machinery maintenance operations can be a significant source of pollution, if exposed to the weather. This site is equipped with adequate indoor shop space to manage the vehicle and machinery maintenance operations. All vehicle maintenance that poses a threat to the environment will be conducted indoors. Equipment Storage Vehicle and machinery exposed to the weather can be a significant source of pollution. Leaking fluids, sediments, and other earthen construction materials remaining on equipment can be carried away with runoff. The facilities storm drain system and SOPs will be effective at containing large particles, but it will not contain contaminates that leach out and become suspended or dissolved in the runoff. This site is equipped with a covered vehicle storage area for all the planned equipment needed for City operations

7 conducted from this facility. The General City Yard Policy SOP is used to define manage the pollutants associated with this operation. Vehicle and Machinery Cleaning Operations Pollutants washed from the vehicles and the detergents used can pollute our water resources. This site is equipped with a covered wash and dump bays that are connected to the sanitary sewer system. The washing of vehicles and equipment is not allowed outside the wash and dump bays. Fueling Operations The Fueling Station is equipped with secondary containment and a Spill Response Kit. It is not covered, however, the facility design puts distance between the Fueling Station and stormwater inlets to provide a buffer increasing the time to contain spills. The facility is also equipped with a water quality box and retention storage volume in the detention pond. These systems provide redundancy and allow containment for spills and pollutants that might be carried with runoff to be trapped and removed. In addition, the Spill Containment and Cleanup, and Pavement Washing SOPs will prevent pollutants from reaching the stormwater system. Street Maintenance Staging Operations The materials stored at this facility for street repair and the staging operations can be a source of pollution when these processes are exposed to weather. This site is equipped with covered areas for asphalt, backfill materials, etc., and plenty of indoor space to store and clean tools. However, there may be times when these covered areas will not be adequate for all projects. The General Construction and Maintenance SOP is used to manage the pollutants associated with this operation. Vacuum and Street Sweeping Staging Operations The improper disposal of waste and cleanup associated with this operation can be a source of pollution and negate one if its primary purposes when these operations are improperly managed and exposed to the weather. This site has a dump and wash bay that is connected to the sanitary sewer system. It also has plenty of indoor space to store the equipment, and to clean tools. The Sweeping and Stormwater System Maintenance SOPs are used to manage the pollutants associated with this operation. Inventory and Miscellaneous Storage

8 The storage of materials can be a source of pollution when it is exposed to the weather. Depending on the stored material, particles can be carried by wind or washed off and carried by runoff. This site has ample indoor storage for most planned inventory and miscellaneous items, but there will be occasions when storage is necessary outdoors. The Inventory and miscellaneous Storage SOP is used to manage the pollutants associated with this pollutant source. General Site Up Keep Staff is responsible to clean up after their operations as defined by the SOPs. However, loose debris will collect from outside and inside sources from normal use and by causes that cannot be practically controlled. General up keep should occur weekly and all staff should be engaged here. The general yard upkeep responsibilities are identified on the site map in Appendix A. SECTION 4: TRAINING The City has a training program in place to ensure that employees know and understand the SOPs that are necessary for effective protection of all water that could enter into the City s storm drain system. The employee training record is kept with the employee training SOP and also in Appendix I on the Stormwater Page of the City s website. SECTION 5: RECORDKEEPING This SMP includes an inspection element that is required to show performance but also to collect the information necessary to warrant updates and improvements. An inspection log for this site will be posted Appendix I of the City s Stormwater page. The site

9 inspection record is kept in Appendix C and also in Appendix I on the Stormwater Page of the City s website. SECTION 6: APPENDICES Appendix A- Site Drawings and Details Appendix B- SOPs Appendix C- Site Inspections Appendix D- Site Evaluations

10 Stormwater Maintenance Plan (SMP)