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HomeMy WebLinkAboutNCS000547_8_IDDE Program_20210610CITY OF ROXBORO Roxboro, North Carolina Illicit Discharge and Elimination Program Prepared by: F I H q�F alley, williams, carmen & king, inc. engineers and architects 740 chapel hill road - post office box 1179 burlington, north carolina 27216-1179 2012 Project No. 10058 Revised: December 2020 Table of Contents 1 Introduction ......................................................................................................................... 1 A. Legal Basis ...................................................................................................................... 1 B. Definitions ....................................................................................................................... 1 C. Categories of Illicit Discharges ........................................................................................ 2 D. Exempt Discharges ......................................................................................................... 3 2. Determine Priority Areas/Identify Hotspots .......................................................................... 3 A. Delineate Subwatersheds ................................................................................................ 3 B. Land Use or Zoning Data ................................................................................................ 3 C. Industrial NPDES Permit Holders .................................................................................... 3 D. Areas known to have problems or complaints .................................................................. 4 E. Septic Systems ................................................................................................................ 4 F. Results of Outfall screening ............................................................................................. 4 3. MS4 Map ............................................................................................................................ 4 4. Dry weather flow screening ................................................................................................. 4 5. Procedures for Illicit Discharge Removal ............................................................................. 5 A. Identifying the Type of Discharge .................................................................................... 5 B. Finding the Source .......................................................................................................... 7 C. Remove/Correct Illicit Discharge ...................................................................................... 7 6. Inspection Program ............................................................................................................. 7 7. Public Education ................................................................................................................. 8 8. Establish Public Reporting Hotline ...................................................................................... 8 9. Training ............................................................................................................................... 8 10. Household Hazardous Waste Collection ............................................................................. 8 11. Recordkeeping and Tracking System .................................................................................. 8 12. Program Assessment and Evaluation ................................................................................. 8 1. INTRODUCTION This document describes the City of Roxboro's plan for identifying and eliminating illicit discharges and connections within its jurisdictional area. This plan has been developed to partially fulfill the requirements of the City's NPDES Stormwater Permit No. NCS000547 issued by the State of North Carolina Department of Environmental Quality, Division of Energy, Mineral, and Land Resources (NCDENR-DEMLR) and the Comprehensive Stormwater Management Plan developed by the City. Much of this plan is based on guidance provided in the Center for Watershed Protection's manual titled Illicit Discharge Detection and Elimination: A Guidance Manual for Program Development and Technical Assessments. This current version of the plan follows successful completion of the original MS4 mapping program. The City of Roxboro is located in both the Roanoke and Neuse River Basins. The City's storm sewer system discharges into portions of Marlowe's Creek, Tanyard Branch, and North Flat River and their tributaries. The land use in the City's jurisdiction is predominately residential or institutional, with very little industry at this point. This plan includes identifying areas likely to have illicit discharges, locating and screening storm sewer system outfalls, developing and maintaining a storm sewer system map, procedures for detecting and removing illicit discharges, and program assessment and evaluation procedures. Much of the storm sewer system within the City of Roxboro's jurisdictional area was mapped during the City's first permit cycle (2012 to 2018). This mapping focused on locating and screening storm system outfalls, locating storm sewer structures, determining drainage areas, and creating a map of the storm sewer system. A. Legal Basis The City adopted an Illicit Discharge Ordinance in 2012. This ordinance is found in the City's Code of Ordinances and provides the City with the basic legal tools necessary to conduct investigations, determine sources of illicit discharges, and enforce the removal of illicit discharges or connections. B. Definitions Illicit Discharge: Any direct or indirect non -storm water discharge to the storm drain system, except as exempted below. Illicit Connections: An illicit connection is defined as either of the following: Any drain or conveyance, whether on the surface or subsurface, which allows an illegal discharge to enter the storm drain system, including but not limited to any conveyances which allow any non -storm water discharge including sewage, process wastewater, and wash water to enter the storm drain system and any connections to the storm drain system from indoor drains and sinks, regardless of whether said drain or connection had been previously allowed, permitted, or approved by an authorized enforcement agency or, Any drain or conveyance connected from a commercial or industrial land use to the storm drain system which has not been documented in plans, maps, or equivalent records and approved by an authorized enforcement agency. City of Roxboro: Illicit Discharge Detection & Elimination Program Page lof9 MS4: Municipal Separate Storm Sewer System. A conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins curbs, gutters, ditches, manmade channels, or storm drains) that transports stormwater to receiving streams, lakes, and/or oceans. C. Categories of Illicit Discharges The following table was developed by MACTEC Engineering & Consulting for the Scripps Institution of Oceanography in San Diego California. It is a summary of the types, characteristics, and examples of illicit discharges. Frequency Continuous: Discharge occurs most or all of the time. Intermittent: Discharge occurs over a short period. (i.e. a few hours a day or a few days a year.) Transitory: Discharge occurs rarely, usually a singular event. Flow Type Sewage and Septage: Flows that are produced from sewer pipes and septic systems. Washwater. Flows generated from a wide variety of activities and operations (i.e. vehicle and equipment washing). Liquid Wastes: Refers to a wide variety of flows such as oil, paint, and process water. Tap Water. Flows derived from leaks and losses during the distribution of drinking water in the water supply system or water from hydrant and fire suppression system flushing. Specific to SIO seawater losses will considered under this category. • Landscape Irrigation: Flows derived from excess potable water used for irrigation enters a storm water conveyance system. • Groundwater and Spring Water. Flows occur when local water table rises above the bottom elevation of the storm water conveyance system and water enters the storm water conveyance system through open joints and cracks, or where open channels or pipes may intercept seeps and springs. • Air Conditioning and Refrigeration Condensate: Flows derived from the condensate produced by air conditioners or refrigerators. • Pools, Fountains, Water Tanks, and Aquariums: Flows derived from leaks and losses from pools, fountains, water tanks, and aquariums and the associated appurtenances. • Aboveground Storage Tanks: Flows derived from leaks and losses from emergency generators and transformers. Mode of Entry • Direct: Discharge is connected directly to the storm water conveyance system through a sewage pipe, shop drain, or other kind of pipe. Tend to produce continuous and intermittent discharges. • Sewage Cross -Connection: A sewer pipe improperly connected to the storm water conveyance system producing a continuous discharge of raw sewage from the pipe. • Straight Pipe: Refers to relatively small diameter pipes or hoses that intentionally bypass the sanitary connection or septic drain fields, producing direct discharges into open channels or streams. • Industrial or Commercial Cross -Connection: Occur when a drain pipe is improperly connected to the storm water conveyance system producing a discharge wash water, process water, or other inappropriate flows into the storm drain pipe (i.e. shop drains). • Indirect. Flows generated outside the storm water conveyance system that enter through storm drain inlets or by infiltrating the joints of the pipe. Tend to produce intermittent or transitory discharges. • Groundwater and Spring Water Seepage: (see Flow Type) • Spills: Transitory discharges that occur when a spill travels across an impervious surface and enters a storm drain inlet (i.e. gasoline from an accident). • Dumping: Transitory discharge created when liquid wastes such as oil, grease, paint, solvents, and various other related fluids are dumped purposefully or ignorantly into the storm water conveyance system. City of Roxboro: Illicit Discharge Detection & Elimination Program Page 2 of 9 * Outdoor Washing Activities: Intermittent or transitory washing activities including, but not limited to, washing of fueling areas, outdoor storage areas, parking lots, and vehicles or equipment. * Non -Target Irrigation from Landscaping: Intermittent discharges from over -watering, misdirected sprinklers, or broken sprinkler heads or pipes that send potable water over impervious surfaces into a storm water conveyance system. D. Exempt Discharges The following Non-stormwater discharges are allowed into the MS4; • Water line flushing • Landscape irrigation • Diverted stream flows • Rising ground waters • Uncontaminated ground water infiltration • Uncontaminated pumped ground water • Discharges from potable water sources • Foundation drains • Air conditioning condensation • Irrigation water • Springs • Water from crawl space pumps • Footing drains • Lawn watering • Individual residential car washing • Flows from riparian habitats and wetlands • Dechlorinated swimming pool discharges • Street wash water • Other non-stormwater discharges for which a valid NPIDES discharge permit has been approved and issued by the State of North Carolina 2. DETERMINE PRIORITY AREAS / IDENTIFY HOTSPOTS To identify the areas within the MS4 with a high potential of illicit discharges and connections, available data was collected and analyzed, and an illicit discharge potential (IDP) was assigned to geographic areas. Outfalls within areas with a higher IDP were screed initially and all other outfalls were screened subsequently. This data is used to guide outfall inspections. Following are the types on information that were initially used to prioritize the MS4. A. Delineate Subwatersheds The MS4 was divided into smaller, more manageable units known as subwatersheds. These are shown on the MS4 Map and are available through GIS. B. Land Use or Zoning Data Land use or zoning maps were used to identify potential generating sites or "hotspots". In general, industrial and commercial land use have a higher potential for illicit discharges than residential. C. Industrial NPIDES Permit Holders Industrial sites produce a wide range of flows that can cause illicit discharges. The most common continuous discharges are operations involving the disposal of rinse water, process water, wash water and contaminated, noncontact cooling water. Spills and City of Roxboro: Illicit Discharge Detection & Elimination Program Page 3 of 9 leaks, ruptured pipes, and leaking underground storage tanks are also a source of indirect discharges. A list of the industrial NPDES stormwater permit holders within the City's jurisdiction will be obtained from NCDEQ and updated annually. These sites will be added to the IVIS4 map and the areas in which they are located will be given a high priority for outfall screening and IVIS4 mapping. D. Areas known to have Droblems or COMDlaints. Informal interviews with City employees are conducted to determine the nature and location of any past complaints that may be related to illicit discharges or connections. These discussions will be supplemented by IDDE recordkeeping to determine hotspots not otherwise identified. This will happen annually within the stormwater program annual reporting process. E. Septic Systems Subwatersheds located outside of the sewer service area are presumably served by septic systems. Initially, these areas were prioritized for mapping due to the potential for failing septic systems. After reviewing these areas, the City has limited jurisdiction over these areas but continues to monitor the IVIS4 in these areas. F. Results of Outfall screening As the outfalls in the City's jurisdiction were mapped, any areas where the outfall density per stream mile is greater than 20 are considered to have a high IDP. Follow-up outfall screening will prioritize these areas. 3. MS4 MAP Identifying and understanding the local storm drainage infrastructure and conveyance system is an important first step in the development of an IDDE program. The City's GPS located GIS map provides that basis and was completed during the first permit cycle. The map includes the IVIS4, subwatersheds, storm drainage outfalls, streets, the water supply watershed area, new development stormwater permits (including permitted and constructed SCIVI's), the wastewater collection system and other GIS and City information. The map is to be updated with improvements on at least an annual basis. The intent of the IVIS4 map is to provide a basis for investigation of stormwater pollution while also providing a guide for future outfall screening and stream walks. 4. DRY WEATHER FLOW SCREENING The City will complete outfall screening and investigate dry weather flows. Initial field screening of the IVIS4 outfalls was conducted during initial mapping activities. During the following permit cycles, the City will conduct outfall screening in a manner so as to screen every outfall at least once per permit cycle. The purpose of the screening is to locate those outfalls that have continuous or intermittent dry weather discharges. Field inspectors will walk the receiving streams identified in the City's stormwater permit, map the locations of stormwater outfalls, record the physical characteristics of the outfall, photograph the outfall, and document physical observations of any dry weather flow that may be present. City of Roxboro: Micit Discharge Detection & Elimination Program Page 4 of 9 The screening will be conducted from late fall to early spring when leaves are off the trees and vegetative undergrowth is minimal. There must be a dry period of at least 48 hours before a screening can be conducted. For each outfall where a dry weather flow is found, the field inspector will check the flow for the physical characteristics shown in the following list. Flow Rate 0 Temperature Odor 0 Deposits/Stains Color 0 Vegetation Conditions Turbidity 0 Floatables When an obvious illicit discharge is found, the field inspector will immediately notify the public works department and track the discharge upstream to its source, if possible (see Section 4). A severity rating, on a scale of 1 to 3, will be assigned for odor, color, turbidity, and floatables and each outfall will be given a designation according to the following criteria: Designation Description 1: Obvious Discharge Outfalls where there is an illicit discharge that doesn't even require sample collection for confirmation. 2: Suspect Discharge Flowing outfalls with high severity on one or more physical indicators. 3: Potential Discharge Flowing or non -flowing outfalls with presence of two or more physical indicators. 4: Unlikely Discharge Non -flowing outfalls with no physical indicators of an illicit discharge. The outfall locations will be recorded on a map and the associated inventory will be maintained in a GIS or database. 5. PROCEDURES FOR ILLICIT DISCHARGE REMOVAL A. Identifying the Type of Discharge Often identifying the type of discharge will help in determining a possible source. The type of investigation will depend primarily on the land use within the outfall drainage area with the goal to identify the most likely type of discharge. In residential areas, generally the most common illicit discharges are sewage and wash water flows. Industrial - commercial areas however, often have flows that are not composed of either sewage or wash water. An exception to this process is for sanitary sewer overflows from the City's wastewater collection system. These will be tracked through the City's collection system program and annually reported within the City's MS4 program as well. City of Roxboro: Illicit Discharge Detection & Elimination Program Page 5 of 9 Most illicit discharges are readily identifiable in the field, such as paint or oil. If the source is not readily identifiable then the flow chart shown below will aid in identifying the type of discharge. The methods shown require some field and laboratory analysis. Analysis for Boron, Ammonia, and Fluoride are required to characterize the discharge as sewage, wash water, tap water, or natural water in residential watersheds. Intermittent flows are difficult to sample. Techniques to collect samples involve partially damming up the pipe where the suspected discharge occurs and returning at a later time to sample the discharge stored behind the dam. Another method involves the use of Optical Brightener Monitoring (OBM) traps. When these absorbent pads are anchored in the pipe or manhole to capture dry weather flows, they can be used to determine the presence of flow and/or detergents. The pads are then retrieved after 48 hours and are observed under a fluorescent light that will indicate if they have been exposed to detergents. These methods, or variations on them, will be used to collect samples from known or suspected intermittent flows. Flow Chart to Identify Illicit Discharges. City of Roxboro: Illicit Discharge Detection & Elimination Program Page 6 of 9 B. Finding the Source The City will attempt to find the source of all dry weather flows. However, since many of these flows may be intermittent or transitory, identifying 100% of dry weather flows is unlikely. For each dry weather discharge, the inspector, after conducting the outfall mapping, documenting the physical characteristics, and performing visual flow observations, will follow the pipe or drainage system upstream in an attempt to identify the general location from which the discharge originates. The goal is to isolate the discharge between two inlets. If the inspector cannot identify the specific source through visual observation, or if the trail of the discharge dissipates, further investigations will be necessary and is likely to require the outfall screen i ng/testi ng noted in portion A. Depending on the circumstances, the City may video those storm sewers that look suspicious to identify pollutant sources that cannot be located through simple visual observation and/or sampling. For example, the City may be able to determine, based on visual observation and/or sampling, that an illicit connection exists between two specific inlets. Video inspection of the stretch of storm sewer between these two manholes could be used to isolate the exact source of the illicit con nection/d ischarge. In addition, letters may be sent to residents and businesses alerting them to the problem that is under investigation to solicit their assistance in finding the source. A building by building evaluation may also be used in areas where a problem has been isolated to a small area. The City may also conduct physical inspection of commercial and/or residential facilities as needed to verify illicit connections detected through visual outfall inspection, sampling, and/or manhole flow observation. As necessary, facility inspections will include dye testing of suspect facility plumbing fixtures. All facility inspections will be documented. C. Remove/Correct Illicit Discharge Once an illicit connection/discharge has been identified and verified, the City will notify the owner in writing and direct them to eliminate the illicit connection/discharge within a specified time frame. The notification will require the owner to inform the City when the connection has been eliminated. The time frame for eliminating the illicit connection or discharge will depend on the type of illicit connection/discharge and how difficult elimination will be. The City will follow up with the owner to ensure that the connection/discharge has been eliminated. If the connection has not been eliminated, the City will enforce its Illicit Discharge ordinance to obtain compliance. 6. INSPECTION PROGRAM All outfalls were screened during mapping and are now screened at least once during each permit cycle. Problem outfalls, and outfalls where illicit discharges were previously detected and eliminated will be inspected more regularly. If two consecutive inspections show no evidence of City of Roxboro: Illicit Discharge Detection & Elimination Program Page 7 of 9 dry weather flow or illicit discharge, the outfall will be inspected once every permit cycle. If a complaint is received concerning a outfall, it will be inspected as soon as possible. 7. PUBLIC EDUCATION The City will be assisted in educating the public by the Clean Water Education Partnership to educate the public about hazards associated with illicit discharges and improper disposal of waste. Public employees, businesses, and the general public will be targeted. 8. ESTABLISH PUBLIC REPORTING HOTLINE The City will make use of the toll -free NCDENR Customer service hotline and the City's primary phone number for reporting. These will be publicized in education materials targeting IDDE and on the City's website. The City has not found the need to have a dedicated hotline that would be answered by the same staff as the normal phone number. After notification, City staff is to notify the City Public Services Director who will coordinate with investigation with the City's contracted stormwater engineer. 9. TRAINING City Public Works staff will receive specific training on screening and inspecting outfalls, identifying, tracking, and removing illicit discharges and connections. Training is to be completed annually when possible. 10. HOUSEHOLD HAZARDOUS WASTE COLLECTION The City will work with Person County to provide household hazardous waste collections. This encourages the general public to properly dispose of hazardous wastes instead of illegally dumping them in the watershed. Currently this occurs approximately once a year. 11. RECORDKEEPING AND TRACKING SYSTEM The City will create and maintain a database that documents all activities associated with this IDDE program including the following: • All outfall screening information. • All MS4 mapping information. • Number of dry weather flows found. • Number of illicit discharges/connections found. • Number of illicit discharges/connections removed. • Number of illicit discharges/connections found through citizen complaints. • Information on video, dye, and/or smoke testing performed. • Number of facility inspections. • Information on industrial facilities within the City's jurisdiction that have NPDES stormwater permits. 12. PROGRAM ASSESSMENT AND EVALUATION City of Roxboro: Illicit Discharge Detection & Elimination Program Page 8 of 9 The IDDE program is to be assessed and evaluated on an annual and permit cycle basis. The program is to be evaluated based upon the following metrics. A productive program is expected to comply with most metrics on an annual basis and all metrics on a permit cycle basis. Program Assessment Item Annual Annual Expectation Permit Cycle Permit Cycle Expectation % Public Works Staff Trained 75% 100% Number of Illicit Discharges Reported • of Illicit Discharges Investigated 100% 100% • of Illicit Discharges Successfully Addressed 100% 100% • of IVIS4 Outfalls Screened 20% 100% New Construction Added to Map 100% 100% Number of Sanitary Sewer Overflows 100% 100% Household Hazardous Waste Collection 1 5 Summary to be provided in annual report City of Roxboro: Micit Discharge Detection & Elimination Program Page 9 of 9