STANDARD OPERATION PROCEDURES UNDERGROUND STORMWATER QUALITY STRUCTURES FOR

Transcription

1 FOR UNDERGROUND STORMWATER QUALITY STRUCTURES A GUIDE TO MAINTAINING PERMANENT STORMWATER QUALITY BEST MANAGEMENT PRACTICES (BMP S) January 24, 2008 Revised: October 30, 2014

2 Table of Contents 1.0 INTRODUCTION BACKGROUND BENEFITS QUALIFICATIONS OF PERSONNEL SAFETY STORMWATER MANAGEMENT FACILITY LOCATION(S) ACCESS AND EASEMENTS TYPICAL INSPECTION & MAINTENANCE INTERVALS INSPECTION FORM MAINTENANCE FORM BaySaver CrystalStream - Hydrodynamic Separation & Pollutant Screening Downstream Defender Stormceptor a In-Line Stormceptor a Inlet Stormceptor c Submerged Stormceptor d Series Stormceptor Vortechs System - System stormwater quality vault VortSentry Snout Inlet Filters a Enviropod b Ultra-Urban Filter with Smart Sponge C HYDROSCREEN COMMENTS/ADDITIONAL INFORMATION Please Note: All Permanent Underground Stormwater Quality Structures have not been included in this guidance document. Please consult the internet for a more complete listing of Underground Stormwater Quality Structure suppliers. The PERMANENT UNDERGROUND STORMWATER QUALITY STRUCTURES and inspection and maintenance procedure descriptions contained within this guidance document were supplied by the product manufacturers. The manufacturers have stated to the City of Loveland that they are capable of providing PERMANENT UNDERGROUND STORMWATER QUALITY STRUCTURES or Best Management Practices (BMPs) that are designed to improve the water quality of stormwater runoff. This guidance document is provided as an aid to property owners who have installed a PERMANENT UNDERGROUND STORMWATER QUALITY STRUCTURE on their property. The inclusion of products within this guidance document does not constitute a recommendation, endorsement, or certification of their qualifications or performance record, nor does the absence of a product from this guidance document constitute a negative endorsement. The City of Loveland has incorporated most of these products into Capital Improvement Projects in an attempt to verify the credentials of these firms, but it is the responsibility of the property owner to be knowledgeable of the products claims to provide treatment for stormwater runoff and to obtain the requisite expertise. Page i

3 1.0 Introduction You have received this packet of information because the City of Loveland has determined that you have one or more permanent UNDERGROUND STORMWATER QUALITY STRUCTURES located on your property. This packet was prepared to help you identify what type of structure(s) you have on your property, show you where the structure(s) is/are located, and describe how often you will need to inspect and perform maintenance on the structure(s) in order to ensure the City of Loveland that the structure(s) is/are performing as intended. 2.0 Background In order to improve the water quality of the City s waterways, in March of 2003 the City of Loveland was required by the State of Colorado to submit a general permit to discharge stormwater. The general permit is comprised of six minimum measures and is available for you to see on the City s Stormwater website at: The goal and objectives of minimum measure number five of the general permit entitled POST- CONSTRUCTION STORMWATER MANAGEMENT is to: (1). Improve the water quality of stormwater runoff to the Maximum Extent Practicable (MEP); (2). Prevent accumulations of soil and debris into the City of Loveland s storm sewers and waterways; (3). Prevent the discharge of chemicals, chemical wastes and other pollutants from entering the City of Loveland s storm sewers and waterways; (4). Protect state waters, waterways and wetlands from damages caused by erosion, sedimentation, chemicals, chemical wastes and other pollutants, and; To ensure the structure(s) perform as intended under this minimum measure the City of Loveland was required to: (a). Provide a mechanism that ensures the adequate long-term operation and maintenance of Best Management Practices (BMPs) installed during development, and; (b). Require regularly scheduled inspections and maintenance of permanent stormwater quality BMPs to ensure they perform as planned. Although Proprietary BMPs or UNDERGROUND STORMWATER QUALITY STRUCTURES are not officially recognized in the Urban Storm Drainage Criteria Manual Volume 3 Best Management Practices developed by the Urban Drainage and Flood Control District (UDFCD) as a permanent stormwater quality BMP they can provide significant stormwater quality benefits for Non-Point Source Pollution also know as polluted stormwater runoff when used under the following conditions: When they are retrofitted into a highly urbanized basin in which site constraints don t allow room for Extended Detention Basins (EDBs) or other nonstructural permanent stormwater quality; When there are numerous existing utilities to work around; When the cost to acquire land to construct EDB(s) and/or other nonstructural permanent stormwater quality BMP(s) is/are prohibitive; When there isn t a viable cost effective alternative for incorporating permanent nonstructural BMPs into a particular development site, or; Page 2

4 As an additional permanent stormwater quality BMP in the treatment train to further reduce contaminants from stormwater runoff before discharge into an EDB or offsite into a waterway. UNDERGROUND STORMWATER QUALITY STRUCTURES should also be recognized as confined spaces for the purposes of entry and maintenance, and as potential vector breeding grounds. If identified as mosquito breeding areas they should be added to the municipal annual mosquito treatment plan. 3.0 Benefits Sediment, oils, and greases are the most significant pollutants in stormwater runoff, but nutrients, pathogens, heavy metals, organics, and organic enrichment also contribute to the degradation of water quality within our waterways. UNDERGROUND STORMWATER QUALITY STRUCTURES are specifically designed to perform the task of removing these materials from stormwater runoff. 4.0 Qualifications of Personnel 4.1 Inspectors Since specialized equipment may be needed to access and properly assess the condition of the UNDERGROUND STORMWATER QUALITY STRUCTURES during inspections, it is highly recommended that inspections be performed by qualified inspectors. 4.2 Maintenance Personnel Maintenance personnel must also be qualified to properly maintain UNDERGROUND STORMWATER QUALITY STRUCTURES. Inadequately trained personnel can be injured or killed and cause additional problems resulting in increased maintenance costs. 5.0 SAFETY There are many safety concerns to consider when dealing with UNDERGROUND STORMWATER QUALITY STRUCTURES. These structures are most often located in parking lots or along roadways. Extreme care needs to be taken to access them. To minimize risks involved when performing inspections and/or maintenance on UNDERGROUND STORMWATER QUALITY STRUCTURES all personnel should be well trained and have the following certifications: Confined Space Training, and; Traffic Control. 6.0 Stormwater Management Facility Location(s) Inspection or maintenance personnel may utilize the stormwater facility map located in APPENDIX A which contains the location(s) of the UNDERGROUND STORMWATER QUALITY STRUCTURE(S) within this development. Page 3

5 7.0 Access and Easements Inspection or maintenance personnel may utilize the stormwater facility map located in APPENDIX A containing the location(s) of the access point(s) and maintenance easements of the UNDERGROUND STORMWATER QUALITY STRUCTURE(S) within this development. 8.0 Typical Inspection & Maintenance Intervals For the UNDERGROUND STORMWATER QUALITY STRUCTURES to perform optimally it is essential that they are properly inspected and maintained per the manufacturer s specifications. Below is a list of the most common UNDERGROUND STORMWATER QUALITY STRUCTURES and the recommended maintenance intervals to be performed so they perform as intended: UNDERGROUND STORMWATER QUALITY STRUCTURES INSPECTION INTERVAL SEDIMENT, TRASH & DEBRIS REMOVAL BAYSAVER Quarterly Annually CRYSTALSTREAM Every 90 days When there is 1 of sediment in front of oil reservoir DOWNSTREAM DEFENDER Inspected & monitored every 6 months Cleaned annually INLET FILTERS Regularly scheduled inspections to determine areas with higher accumulations and/or contaminant potential As needed for sediment & debris removal. Base cleaning program on those site-specific situations. SNOUT Monthly monitoring for the 1 st year and at least quarterly thereafter When the sump is half full STORMCEPTOR Quarterly Varies VORTECHS SYSTEM Quarterly When sediment depth has accumulated to within 6 inches of the dry-weather water surface elevation. VORTSENTRY Quarterly As Necessary 9.0 Inspection Form An INSPECTION FORM shall be completed by the person(s) actually conducting the inspection. All the features listed on the form must be identified at the time of the inspection. The INSPECTION FORM provides a record of each inspection performed during the year. The INSPECTION FORM shall be filled out for each structure in the field after the completion of the inspection by the inspector. Each INSPECTION FORM shall be reviewed by an authorized agent of the property owner. The original INSPECTION FORM shall be kept for a period of five years and a copy of the INSPECTION FORM shall be submitted to the City of Loveland at the end of each year to the attention of the Stormwater Quality Specialist at the following address: Public Works Administration Building Public Works Department - Stormwater 2525 West 1 st Street Loveland, CO Page 4

6 10.0 Maintenance Form A variety of maintenance activities, separated into categories, are identified on the MAINTENANCE FORM. All maintenance activities performed during the operation must be identified on the form. These maintenance activities are described in more detail in this Manual. The MAINTENANCE FORM provides a record of each maintenance operation performed by the maintenance contractor(s). The MAINTENANCE FORM shall be filled out in the field after the completion of the maintenance operation by the contractor completing the required maintenance. The MAINTENANCE FORM shall then be reviewed by an authorized agent of the property owner. The original MAINTENANCE FORM shall be kept for a period of five years, and a copy of the MAINTENANCE FORM shall be submitted at the end of each year to the City of Loveland to the attention of the Stormwater Quality Specialist at the following address: Public Works Administration Building Public Works Department - Stormwater 2525 West 1 st Street Loveland, CO Underground Stormwater Quality Structures Although there are many UNDERGROUND STORMWATER QUALITY STRUCTURES available to choose from, the inspection & maintenance procedures are very similar for each of them. Following is a list of some of the more familiar UNDERGROUND STORMWATER QUALITY STRUCTURES and a brief description of the inspection and maintenance procedures recommended for them BaySaver The BaySaver Separation System is a physical separation system that meets regulations for non-point source pollution control. The system operates using gravity flow and density differences to remove oils, suspended sediments, and floatables (trash and other floating debris) from stormwater runoff. Easy to specify, install, inspect, and maintain, the BaySaver Separation System helps you avoid using the valuable acreage necessary for other types of best management practices (BMPs). Figure 1: BAYSAVER SEPARATION SYSTEM The BaySaver Separation System is composed of two standard pre-cast manholes and the BaySaver Separator Unit. The two manholes allow the removal and storage of pollutants, while the separator unit directs the flow of water to provide the most efficient treatment possible. Figure 1 shows a cutaway view of the complete BaySaver Separation System Inspection Procedures Inspection can be performed through visual observation and by measuring sediment levels by removing the manhole covers. The inspector or maintenance contractor can gain unobstructed access to the bottom of the manholes, making confined space entry unnecessary. Site-specific inspection scheduling, coupled with maintenance that can be completed from above grade, results in more efficient maintenance at a lower cost. Beginning the day that construction is complete, periodic inspection determines the cleaning frequency. In the first year, the system should be inspected quarterly to determine pollutant loading rates. Page 5

7 Maintenance Procedures Most systems require yearly cleaning given normal loadings and sizing. Maintenance is needed when the sediment accumulation has reached a height of two feet from the floor in either manhole. Like any system that collects pollutants, the BaySaver Separation System must be maintained for continued effectiveness. Maintenance is a simple procedure and is performed using a vacuum truck or similar equipment. Access to the contaminant storage is available through 30 manhole covers in each structure. Vacuum hoses can reach the entire floor area of both manholes, so all sediments can be evacuated. The BaySaver Separation System was designed to minimize the volume of water removed during routine maintenance, thus reducing disposal costs. The entire maintenance procedure typically takes from 2 to 4 hours, depending on the size of the system. The recommended maintenance procedure for the BaySaver Separation System follows Maintenance Instructions Maintenance procedures are as follows: Remove the two manhole covers to provide access to the contaminant storage. Remove all water, debris, oils, and sediment from the storage manhole using a vacuum truck or other equipment. Using a high pressure hose, clean the storage manhole and remove the cleaning water using the vacuum truck Using a submersible pump, pump the bulk of the water from the primary manhole into the clean storage manhole. The pump intake must be kept below the water surface to avoid pumping surface oils, and pumping must be stopped when the water surface falls to a level one foot above the accumulated sediments Remove the remaining water and sediment from the primary manhole using a vacuum truck or other equipment Using a high pressure hose, clean the primary manhole and remove the cleaning water using the vacuum truck Fill the primary manhole with water to the invert of the BaySaver Separator Unit. Fill the storage manhole with water to a depth of 8 feet Replace the two manhole covers Dispose of the contaminated water at an approved facility. Local regulations often prohibit discharge of this material to the sanitary sewer; the local sewer authority must authorize such a discharge. This procedure is intended to remove all the collected pollutants from the system while minimizing the volume of water that must be disposed. Additional local regulations may apply to the maintenance procedure. Safe and legal disposal of pollutants is the responsibility of the maintenance contractor; therefore maintenance should be performed only by a qualified contractor. Page 6

8 11.2 CrystalStream - Hydrodynamic Separation & Pollutant Screening Inspection Overview Inspection can be performed through visual observation and by measuring sediment levels by removing the manhole covers. The inspector or maintenance contractor can gain unobstructed access to the bottom of the structure via the manhole(s), making confined space entry unnecessary. Site-specific inspection scheduling, coupled with maintenance that can be completed from above grade, results in more efficient maintenance at a lower cost. Beginning the day that construction is complete, periodic inspection determines the cleaning frequency. In the first year, the system should be inspected once every six months to determine pollutant loading rates. The unit is designed and specified in most applications to comply with the non-point source mandates of the Clean Water Act and the NPDES regulations. These regulations state that any BMP (Best Management Practice) needs to be inspected every 90 days and cleaned and maintained as needed. Many local regulations have similar requirements and all federal, state and local requirements must be met. CrystalStream Technologies recommends visual inspection on a 30-day cycle as well as sediment depth inspection, during the construction phase. The unit inspection is done to determine the operational status of the unit and determine if a cleaning cycle is necessary as well as to meet any jurisdictional ordinance requirements. All inspections must be documented (Appendix 2). When construction has been completed and the site has been stabilized, the CST unit should be inspected every 90 days and cleaned when there is 1 of sediment in front of the oil reservoir Inspection Procedures As per the following: The unit should be visually inspected from the surface to determine the integrity of access points. Look for broken hinges or broken or missing handles. A qualified welder should repair any broken hinges immediately. Inspect bolts on lid angle iron and look for loose red heads on angle iron. Replace red heads as needed. Re-paint the lid, with a rust resistant paint as necessary The access should be opened and secured properly A visual inspection should be made of the trash basket at the front of the unit to determine capacity and type of material trapped A visual inspection should be made of the water surface in the front of the unit to determine oil sheen or blanket A visual inspection should be made of the oil and hydrocarbon reservoir to determine amount of oil/water trapped and the historical high-water level in the unit A visual inspection of the water surface in the rear of the unit should be made and any pollutants noted. Page 7

9 Inspect the aluminum mesh in the trash basket. Replace as needed. Inspect the basket frame for cracks or damage. Repair as needed A visual inspection should be made of the pipe connections to the unit and any material decay or improper installation noted. Pipes should be cut flush with the interior wall of the unit and properly mudded in. If upon inspection it is noted that the pipes are not cut flush, or are not mudded in, contact the contractor and require that he correct this immediately Inspect baffles to ensure that they are properly seated into the brackets. Also note if there is any damage to baffles (bowing). Reseat baffles if necessary Inspect oil reservoir for cracks or damage. Check the welds around the oil reservoir for wear or damage and note any repair work necessary. A qualified welder must perform all repair work to the welds on the oil reservoir during the routine cleaning Inspect the riser for cracks in the concrete walls. Repair as required during the routine cleaning A silt gauge should be used to determine sediment depth as shown in Appendix 1. Check the silt/sediment level behind the trash basket and in front of the oil reservoir The access for cleaning should be evaluated and documented. The truck cleaning these units requires a stable roadway capable of withstanding 15,000 pounds Any changes in the area tributary that are evident should be noted Replace the access point covers carefully Note the condition of the area surrounding the unit on the inspection report. (Example: grass, dirt, rocks, sink holes) and report any hazardous conditions to the appropriate supervisor An inspection report should be completed, with a copy staying on site and a copy being sent to the local jurisdiction. The inspection procedures for the traffic units are similar to those for the non- traffic units with the exception of the sediment depth evaluations as shown in Appendix 1 and an inspection of the grate and Frame and Ring and Cover. Also proper precautions should be taken in Traffic situations as specified in the Safety section of this manual. NOTE: When there has been an obvious gasoline spill or other flammable/hazardous material in the unit, immediate notification should be given to the owner and jurisdictional authorities. This manual is for routine cleaning of storm water debris and any unusual occurrences should be left to properly trained and equipped individuals Cleaning Overview The cleaning of the unit is the essential element to the operational success of the CrystalStream Device. The pollutant removal capacity of the device will eventually cause the equipment to fail without proper maintenance and additionally not achieve the goals of the installation. The cleaning cycle is dependent on a number of factors including pollutant load, rainfall, and time of year, basin changes, upstream mitigation tactics and Page 8

10 installation. Based on the variety of factors, a cleaning schedule can be consistent or vary widely on the same device. This highlights the importance of the inspection process in the overall maintenance and integrity of the unit. The cleaning is generally done with a two-person crew and a vacuum pump system. The duration of the maintenance will depend on a number of factors but can typically be done in about 2.5 hours with properly trained individuals Cleaning Procedures Surface Cleaning If the cleaning of the unit is to be preformed from the surface, the operator should expect a longer cleaning time and the potential for additional disposal charges. The front chamber of the unit will contain the trash and debris in the trash basket, any floating hydrocarbons that have not been skimmed into the oil/hydrocarbon reservoir and accumulated sediment on the bottom of the unit. Cleaning procedures are as per the following: The unit should be visually inspected from the surface to determine the integrity of the tread plate lid, Aluminum Hatch or other access A visual inspection of the unit should be done to evaluate structural integrity and determine if any impacted material is present in the device. If there has been a hazardous spill see Section 4.6 NOTE: When there has been an obvious gasoline spill or other flammable/hazardous material in the unit, immediate notification should be given to the owner and jurisdictional authorities. This manual is for routine cleaning of storm water debris and any unusual occurrences should be left to properly trained and equipped individuals The Trash Basket should be cleaned by either using a trash netting system or vacuum truck. If cleaning using netting system, this material can be disposed of in trash bags in the normal manner The surface oil/hydrocarbon separation zone in the front chamber should be removed either with sorbants or with a vacuum truck The stormwater contained in the area between the surface water and the sediment accumulation can be decanted to minimize the amount of disposal required. Any downstream discharge needs to be after the surface cleaning and only down to the level of the bottom of the oil/hydrocarbon reservoir or the top of the sediment accumulation. Any pollutants discharged downstream are the responsibility of the cleaning operator The oil/hydrocarbon reservoir needs to be evacuated by the vacuum equipment The sediment accumulated in the front and rear chamber can be removed by the vacuum equipment The unit should be pressure washed down to remove any pollution attached to the baffles, walls or hydrocarbon reservoir All parts should be inspected for wear and tear and documented A maintenance report (Appendix 3) should be completed, with a copy staying on site and a copy being sent to the local jurisdiction. Page 9

11 Cleaning Procedures Confined Space Entry The cleaning procedures are similar for confined space entries except that the OSHA guidelines apply and need to be followed. The confined space entry allows the crew to do a better job of cleaning the unit and allows for the time needed and disposal cost to be reduced. As per the following: CAUTION! Any inspection done in a traffic area must meet the CDOT guidelines for roadway work and additional safety procedure will be necessary. CAUTION! All OSHA confined space requirements should be met while cleaning this unit The unit should be visually inspected from the surface to determine the integrity of the tread plate lid A visual inspection of the unit should be done to evaluate structural integrity and determine if any impacted material is present in the device. If there has been a hazardous spill see section 4.6. NOTE: When there has been an obvious gasoline spill or other flammable/hazardous material in the unit, immediate notification should be given to the owner and jurisdictional authorities. This manual is for routine cleaning of storm water debris and any unusual occurrences should be left to properly trained and equipped individuals A ladder should be inserted on the front side of the unit between the baffles and a sorbant blanket laid on the surface of the water to collect any free oil floating on the surface In most units, the trash basket and baffles can be removed to allow easier access to the bottom of the unit Inspect the aluminum mesh in the trash basket. Replace as needed The Trash Basket should be cleaned and directly disposed of in garbage bags The stormwater contained in the area between the surface water and the sediment accumulation can be decanted to minimize the amount of disposal required. Any downstream discharge needs to be after the surface cleaning and only down to the level of the bottom of the oil/hydrocarbon reservoir or the top of the sediment accumulation. Any pollutants discharged downstream are the responsibility of the cleaning operator The unit should be pressure washed down to remove any pollution attached to the baffles, walls or hydrocarbon reservoir The ladder can be used to get on to the unit floor and remove the rest of the water and sediment from the bottom of the unit The walls should be wiped down in the front with a sorbant blanket The fresh coconut fiber mesh should be replaced in the frame and the frame assembly returned to the unit. Page 10

12 All parts should be inspected for wear and tear and documented Remove all equipment from the unit. Replace the manhole cover and the grate in the concrete lid A maintenance report (Appendix 3) should be completed, with a copy staying on site and a copy being sent to the local jurisdiction Downstream Defender The Downstream Defender (Figure 2) is an advanced Hydrodynamic Vortex Separator that is specifically designed to provide high removal efficiencies of settleable solids and their associated pollutants, oil, and floatables over a wide range of flow rates. Its flow-modifying internal components have been developed from extensive full-scale testing, CFD modeling and over thirty years of hydrodynamic separation experience in wastewater, combined sewer and stormwater applications. These internal components distinguish the Downstream Defender from simple swirl-type devices and conventional oil/grit separators by minimizing turbulence and head losses, enhancing separation, and preventing washout of previously stored pollutants. The high removal efficiencies and inherent low head losses of the Downstream Defender allow for a small footprint making it a compact and economical solution for non-point source pollution. Figure 2: DOWNSTREAM DEFENDER Inspection Procedures During the first year of operation, the unit should be inspected and monitored every six months to determine the rate of sediment and floatables accumulation. A probe can be used to determine the level of solids in the sediment storage facility. This information can then be used to establish a routine maintenance schedule Maintenance Procedures The Downstream Defender is designed with no moving parts, requires no external power source and is fabricated with durable non-corrosive components. Maintenance is therefore limited to monitoring accumulations of stored pollutants and periodic cleanouts. When sediment has accumulated to the specified depth, the contents should be removed by sump vac. In most situations, it is recommended that the units be cleaned annually. In between storm events, the water level in the Downstream Defender drains down to the invert of the outlet pipe (see Figure 2). This keeps the unit wet so that oil and floatables stored on the water surface in the outer annulus are separated from sediment stored below the benching skirt. Storing oil and sediment in isolated locations provides Figure 2: Sump-vac procedure to remove sediment the option for other disposal methods, such as adsorbent pads. Additionally, in a wet unit the stored sediment is unable to solidify which allows for a simple vactor clean-out procedure. Page 11

13 A commercially or municipally owned sump-vac is used to remove captured sediment and floatables. The frequency of the sump vac procedure is determined in the field after installation. Monitoring/clean-out ports are located in the top of the manhole and provide access to the isolated pollutant storage volumes. The floatables access port is above the outer annular space between the dip plate and the manhole wall, where floatables are retained. The sediment removal access port is located directly over the hollow center shaft, which leads to the sediment storage facility below the benching skirt. To prevent floatables and oils from entering the sediment sump storage volume, removing oil and floatables prior to removing sediment is recommended. The vactor procedure for a typical 6-ft diameter Downstream Defender takes less than 30 minutes and removes about 1240 gallons of water in the process. For pollutant storage volumes and estimated volumes of water removed for each size model during clean-out please contact Hydro International and request a copy of the Downstream Defender Operation and Maintenance instructions. This procedure is intended to remove all the collected pollutants from the system while minimizing the volume of water that must be disposed. Additional local regulations may apply to the maintenance procedure. Safe and legal disposal of pollutants is the responsibility of the maintenance contractor; therefore maintenance should be performed only by a qualified contractor Stormceptor The Stormceptor relies on an inverted siphon concept to convey low flows through a circular chamber and then back up through an outlet pipe. A small weir captures the low flows while high flows bypass overtop and continue down the storm sewer system. All of the treatment occurs within one round manhole. Even during high flow rates that bypass the weir, some larger bed load sized material may still get captured. Sediment, oil, and grease are captured and stored beneath the weir structure in the lower part of the manhole. 11.4a In-Line Stormceptor The In-Line Stormceptor is the most commonly installed model. Each unit is constructed from pre-cast concrete components and a patented fiberglass insert. 11.4a-1 Normal (Low) Flow Operating Conditions Under normal operating conditions (more than 90% of all storm events), stormwater flows into the upper chamber and is diverted by a u-shaped weir, into the separation holding chamber. Right angle outlets direct flow around the circular walls of the chamber. Fine and coarse sediments settle to the floor of the chamber, while the petroleum products rise and become trapped beneath the fiberglass insert. 11.4a-1 In-Line Stormceptor Normal (Low) Flow Operation Page 12

14 11.4a-2 High Flow (By-Pass) Operating Conditions During infrequent, high flow events (less than 10% of all storm events), peak stormwater flows pass over the diverting weir and continue into the downstream storm sewer system. This by-pass activity creates pressure equalization across the by-pass chamber, preventing scouring and resuspension of previously trapped pollutants. Stormceptor is the only device with an internal by-pass that prevents scouring of trapped pollutants. The In-Line Stormceptor has been proven in laboratory and field tests to remove over: 80% of Total Suspended Solids, and; 95% of free oils and hydrocarbon spills. 11.4a.1 Maintenance Procedures - In-Line Stormceptor 11.4a-2 In-Line Stormceptor High Flow (By-Pass) Mode Operation You can inspect and maintain the In-Line Stormceptor from the surface, without entry into the unit. Perform maintenance once the stored volume reaches 15% of the Stormceptor capacity, or immediately in the event of a spill. Maintenance intervals vary depending on the application. Therefore, we recommend quarterly inspections during the first year of installation, so you can accurately establish the maintenance schedule. Remove oil and sediment through the 24-inch diameter outlet riser pipe. Alternatively, you may remove floatables and hydrocarbons through the 6-inch oil inspection port. The requirements for the disposal from Stormceptor are similar to that of any other Best Management Practice (BMP). Consult local guidelines or your Stormceptor Area Marketing Manager prior to disposing the separator contents. The In-Line Stormceptor has been applied numerous times as an NPDES Phase I Best Management Practice, and is an ideal solution for communities dealing with the NPDES Phase II Regulations. 11.4a Inlet Stormceptor The Inlet Stormceptor is a 48-inch diameter pre-cast concrete structure with a patented fiberglass insert that takes the place of a traditional inlet structure in a storm sewer system. The insert extends into the treatment chamber, providing dual wall containment of hydrocarbons. 11.4b-1 Normal (Low) Flow Operating Conditions Under normal operating conditions (more than 90% of all storm events), storm water flows into the upper chamber and is diverted by a sloped weir into the lower chamber. Flow is diverted by horizontal outlets around the walls of the lower chamber, settling out coarse and fine sediments to the floor of the chamber. Petroleum products rise and become trapped beneath the fiberglass insert. 11.4b-1 Inlet Stormceptor Normal (Low) Flow Conditions Page 13

15 11.4b-2 High Flow (By-Pass) Operating Conditions During infrequent, high flow events (less than 10% of all storm events), storm water flows pass over the diverting weir into the downstream sewer system, preventing scouring of previously trapped pollutants. The high flow by-pass prevents previously collected pollutants from scour and re- suspension. The Inlet Stormceptor is an excellent Best Management Practice, because it saves the designer the cost of providing a traditional inlet structure upstream of a conventional treatment device in small drainage areas. The Inlet Stormceptor is in use across North American and Australia as a sediment and spill containment device, and has been successfully used as an NPDES Phase I tool. 11.4b.1 Maintenance Procedures - Inlet Stormceptor You can inspect and maintain the Inlet Stormceptor from the surface, without entry into the unit. Perform maintenance once the stored volume reaches 15% of the Stormceptor capacity, or immediately in the event of a spill. Maintenance intervals vary depending on the application. Therefore, we recommend quarterly inspections during the first year of installation, so you can accurately determine the maintenance schedule. The inlet drop pipe has a tapered insert connected to a handle. Once you remove the handle, remove oil and sediment from the 12-inch diameter inlet drop pipe. The requirements for the disposal from Stormceptor are similar to that of any other Best Management Practice (BMP). Consult local guidelines or your Stormceptor Area Marketing Manager prior to disposing the separator contents. 11.4c Submerged Stormceptor The Submerged Stormceptor is designed to remove total suspended solids, free oil, and other pollutants from stormwater run-off in partially submerged pipes. The pre-cast sections are manufactured in easy-to-assemble components. A customized weir separates the upper (by-pass) and lower (treatment) chambers. 11.4c-1 Normal (Low) Flow Operating Conditions The Submerged Stormceptor operates much like the In-Line Stormceptor. The submerged design includes a customized weir height (depending on the average water level in the storm sewer) and two inlet drop pipes. 11.4c-1 Submerged Stormceptor Normal (Low) Flow Conditions 11.4b-2 Inlet Stormceptor High Flow (By-Pass) Conditions Under normal operating conditions (more than 90% of all storm events), the Submerged Stormceptor is effective for free oil and sediment removal. The lower drop pipe, located at the inlet of the storm sewer, is always submerged. This drop pipe transports suspended solids and bed load sediment into the treatment chamber. The higher drop pipe transports lighter material (free oil) and floatables into the separation chamber. Page 14

16 11.4c-2 High Flow (By-Pass) Operating Conditions During infrequent, high flow events (less than 10% of all storm events), water is conveyed over the internal by-pass weir directly to the downstream storm sewer. This by-pass activity prevents high velocities of water from entering the treatment chamber. The Submerged Stormceptor is not effective for oil removal under fully submerged conditions. 11.4c.1 Maintenance Procedure Submerged Stormceptor 11.4c-2 Submerged Stormceptor High Flow (By-Pass) Conditions Inspect and maintain the Submerged Stormceptor from the surface, without entry into the unit. Perform maintenance once stored volume reaches 15% of the Stormceptor capacity, or immediately in the event of a spill. Maintenance intervals vary depending on the application. Therefore, we recommend quarterly inspections during the first year of installation, so you can accurately establish a maintenance schedule. Remove oil and sediment through the 24-inch diameter outlet riser pipe. Alternatively, you may remove floatables and hydrocarbons through the 6-inch oil inspection port. The requirements for the disposal from Stormceptor are similar to that of any other Best Management Practice (BMP). Consult local guidelines or your Stormceptor Area Marketing Manager prior to disposing the separator contents. The Submerged Stormceptor has been successfully installed in coastal areas and other submerged pipe conditions. 11.4d Series Stormceptor The Series Stormceptor is designed to treat run-off from larger drainage areas remove total suspended solids, free oil, and other pollutants from stormwater run-off in partially submerged pipes. The Series Stormceptor consists of two structures. The first structure acts as a flow splitter, diverting half of the flow into the first treatment chamber, and allowing the second half of the flow to travel through the unit to the second treatment chamber. The Series Stormceptor units contain the patented internal by-pass inherent in all Stormceptor designs, preventing scour and resuspension during high flows, which have hampered the performance of conventional separator systems. 11.4d-1 Normal (Low) Flow Operating Conditions Under normal (frequent) operating conditions, stormwater enters the upper by-pass chamber of the first structure. Half of the flow is diverted by a u-shaped weir into the separation/holding chamber of the first structure. This downward flow is directed, by right-angle outlets, around the circular walls of the chamber. Fine and coarse sediment settle to the floor of the chamber, while the petroleum products rise and become trapped beneath the fiberglass insert. The half of the flow which is not diverted in the lower chamber continues through the first structure to the second structure. This remaining flow is diverted into the lower chamber of the 11.4d-1 Series Stormceptor Normal (Low) Flow Conditions Page 15

17 second structure. Suspended solids and floatables are separated as they are in the first chamber. 11.4d-2 High Flow (By-Pass) Operating Conditions During infrequent high flow events, peak stormwater flows will pass over the diverting weirs in the first and second chamber and continue through the by-pass chamber into the downstream sewer system. This bypass activity creates pressure equalization across both units, preventing scouring. A portion of incoming sediment continues to be diverted by the weirs in the first and second structure into the treatment chamber. 11.4d-2 Series Stormceptor High Flow (By-Pass) Conditions 11.4d.1 Maintenance Procedure Series Stormceptor You can inspect and maintain the Series Stormceptor from the surface, without entry into the unit. Perform maintenance once the stored volume reaches 15% of the Stormceptor capacity, or immediately in the event of a spill. Maintenance intervals vary depending on the application. Therefore, we recommend quarterly inspections during the first year of installation, so you can accurately establish the maintenance schedule. Remove oil and sediment through each of the 24-inch diameter outlet riser pipes. Alternatively, you may remove floatables and hydrocarbons through the 6-inch oil inspection port. Both steps must be performed in each of the two structures. The requirements for the disposal from Stormceptor are similar to that of any other Best Management Practice (BMP). Consult local guidelines or your Stormceptor Area Marketing Manager prior to disposing the separator contents. The In-Line Stormceptor has been applied numerous times as an NPDES Phase I Best Management Practice, and is an ideal solution for communities dealing with the NPDES Phase II Regulations. Page 16

18 11.5 Vortechs System - System stormwater quality vault The Vortechs System stormwater quality vault is a multi-chambered rectangular vault that uses a baffle wall, a weir, an orifice, and a circular swirl concentrator to remove floating hydrocarbons, contaminated sediment, debris, trash, oils, and grease from stormwater Inspection Procedures By removing the manhole covers, the inspector or maintenance contractor can gain unobstructed access to the bottom of the manholes, making confined space entry unnecessary. Site-specific inspection scheduling, coupled with maintenance that can be completed from above grade, results in more efficient maintenance at lower cost. Inspection is the key to effective maintenance and is easily performed on the Vortechs System. Vortechnics recommends ongoing quarterly inspections of the grit chamber for accumulated contaminants. Pollutant deposition and transport may vary from year to year and quarterly inspections will help ensure that the system is cleaned out at the appropriate time. Inspections should be performed more frequently where site conditions Page 17

19 may cause rapid accumulation of pollutants. The Vortechs System should be cleaned when inspection reveals that the sediment depth has accumulated to within six inches of the dry-weather water surface elevation. This determination can be made by taking two measurements with a stadia rod or similar measuring device; one measurement from the manhole opening to the top of the sediment pile and the other from the manhole opening to the water surface. The system should be cleaned out if the difference between the two measurements is six inches or less. To avoid underestimating the volume of sediment in the chamber, the measuring device must be lowered to the top of the sediment pile carefully. Finer, silty particles at the top of the pile typically offer less resistance to the end of the rod than larger particles toward the bottom of the pile. In Vortechs System installations where the risk of large petroleum spills is small, liquid contaminants may not accumulate as quickly as sediment. However, an oil or gasoline spill should be cleaned out immediately. Motor oil and other hydrocarbons that accumulate on a more routine basis should be removed when an appreciable layer has been captured Maintenance Procedures One of the advantages of the Vortechs System stormwater quality vault is the ease of maintenance. Like any system that collects pollutants, the Vortechs System stormwater quality vault must be maintained for continued effectiveness. Maintaining the Vortechs System is easiest when there is no flow entering the system. For this reason, it is a good idea to schedule the clean out during dry weather. Clean out of the Vortechs System with a vacuum truck is generally the most effective and convenient method of excavating pollutants from the system. If a vacuum truck is not available, a clamshell grab may be used, although it is not as effective. Accumulated sediment is typically evacuated through the manhole over the grit chamber. Simply remove the cover and insert the vacuum hose into the grit chamber. As water is evacuated, the water level outside of the grit chamber will drop to the same level as the crest of the lower aperture of the grit chamber. It will not drop below this level due to the fact that the bottom and sides of the grit chamber are sealed to the tank floor and walls. This water lock feature prevents water from migrating into the grit chamber, exposing the bottom of the baffle wall. Floating pollutants will decant into the grit chamber as the water level there is drawn down. This allows most floating material to be withdrawn from the same access point above the grit chamber. If maintenance is not performed as recommended, sediment may accumulate outside the grit chamber. If this is the case, it may be necessary to pump out all chambers. It is a good idea to check for accumulation in all chambers during each maintenance event to prevent sediment buildup in those areas. To remove oil, grease, and other hydrocarbons, it may be preferable to use adsorbent pads since they are usually less expensive to dispose of than the oil/water emulsion that may be created by vacuuming the oily layer. Trash can be netted out if you wish to separate it from the other pollutants. Manhole covers should be securely sealed following cleaning activities, to ensure that surface runoff does not leak into the unit from above. This procedure is intended to remove all the collected pollutants from the system while minimizing the volume of water that must be disposed. Additional local regulations may apply to the maintenance procedure. Safe and legal disposal of pollutants is the responsibility of the maintenance contractor; therefore maintenance should be performed only by a qualified contractor. Page 18

20 11.6 VortSentry Ideally suited for applications where stormwater regulations require that pollutants are reduced to the maximum extent practicable, the VortSentry can be used as a standalone BMP or as a pre-treatment system in conjunction with other stormwater treatment devices. All 2. Inlet Aperture At low flow rates, all runoff is directed through the inlet aperture where it enters the treatment chamber tangentially. 3. Treatment Chamber Gravitational separation of floating and sinking pollutants is enhanced by the gentle swirling motion in the treatment chamber, which causes the settleable solids to sink and form a conical pile in the storage sump. 1. Inlet Stormwater runoff is conveyed into the unit through the inlet Flow Partition At higher flow rates, a portion of the runoff will be diverted over the flow partition and around the treatment chamber, while settleable solids are directed into the treatment chamber. 6. Outlet Flow Control Flow rates through the treatment chamber are limited by the outlet flow control orifice. 4. Treatment Chamber Baffle Trash, hydrocarbons and other floating debris are retained in the treatment chamber by the baffle wall, which extends below the resting water surface elevation. VortSentry models are configured with a flow partition to ensure that the rate of flow through the treatment chamber will not cause pollutant re-entrainment, even as the total flow rate through the system increases. The VortSentry features a round concrete manhole structure for easy installation (often without the use of a crane) and unobstructed maintenance access. With its small footprint, the VortSentry is ideal for tight sites and retrofits Snout The SNOUT is a plastic vented hood that is a low-cost stormwater BMP that prevents oil, grit and floatable debris from polluting our waterways. The SNOUT covers the outlet pipe opening in an inlet reducing floatable trash and debris, free oils, and other solids from stormwater discharges. The SNOUT hood mounts directly to the wall, covering the outlet pipe of a catch basin or other stormwater quality structure which incorporates a deep sump. The SNOUT forms a baffle in the structure which collects floatables and free oils on the surface of the captured stormwater, while permitting heavier solids to sink to the bottom of the sump. 7. Head Equalizing Baffle The head equalizing baffle allows operating rates in the treatment chamber to remain relatively constant even as flow rates in the inlet chamber increase substantially, which minimizes washout potential. Page 19

21 Other features include an anti-siphon vent, a watertight access to the outlet pipe for cleaning, and easy installation. It is also highly corrosion resistant. As per the following: Monthly monitoring for the first year of a new installation after the site has been stabilized Measurements should be taken after each rain event of.5 inches or more, or monthly, as determined by the local weather conditions Checking sediment depth and noting the surface pollutants in the structure will be helpful in planning maintenance. The pollutants collected in the SNOUT equipped structures will consist of floatable debris and oils on the surface of the captured water, and grit and sediment on the bottom of the structure It is best to schedule maintenance based on solids collected in the sump. Optimally, the structure should be cleaned when the sump is half full (e.g. when 2 feet of material collects in a 4 foot sump, clean it out) Structures should also be cleaned if a spill or other incident causes a larger than normal accumulation of pollutants in a structure Maintenance is best done with a vacuum truck. If oil absorbent hydrophobic booms are being used in the structure to enhance hydrocarbon capture and removals, they should be checked on a monthly basis, and serviced or replaced when more than 2/3 of the boom is submerged, indicating a nearly saturated state All collected wastes must be handled and disposed of according to local environmental requirements Inlet Filters Inlet Filters are specifically designed to remove debris, trash, sediment, and other pollutants from stormwater runoff entering the storm drain. 11.8a Enviropod The Enviropod fits catch basins and curb inlets to catch and/or remove a significant portion of trash, debris and other pollutants from water entering the storm drain. The maintenance-friendly manhole curb inlet design makes it easy to access and it has a High flow bypass to prevent flooding. 11.8a.1 Maintenance - Enviropod Maintenance is straightforward, efficient and cost-effective and can be performed using: Stormwater Management staff (Full Service); working with owners who prefer to perform their own maintenance (Self Service with Cartridge Exchange), or; by contracting the maintenance with a third party. The ENVIROPOD is designed to drain over time, eliminating substantial amounts of standing water. This reduces disposal volume and maintenance time, resulting in lower maintenance costs. Annual maintenance is typically recommended for optimum efficiency of all stormwater systems. However, the frequency will ultimately depend on the site conditions, rainfall patterns and pollutant loading. Page 20

22 11.8a.1.1 Full Service The Stormwater Management maintenance crew evaluates your system to ensure that it continues to operate per site-specific design criteria. A Certificate of Compliance is provided verifying that the system continues to meet the original design standards whenever maintenance and/or inspections are provided. This Certificate is sent to the owner and a copy can be sent to the local stormwater authority upon request. 11.8a.1.2 Self Service with Cartridge Exchange Stormwater Management provides Operation and Maintenance Guidelines with each ENVIROPOD system, outlining the recommended maintenance procedure. The Cartridge Exchange program is available for owners who chose to perform their own maintenance. Fresh cartridges are provided in exchange for empty ones. StormFilter maintenance can be performed while the vault is dry, making it especially easy and cost-effective to maintain. 11.8a Remove the cartridge hood and either manually or with a vacuum truck, dispose of the residuals. 11.8a a a Clean remaining trash, debris and sediments from the vault. Replace the empty filter cartridge with a recharged cartridge provided by Stormwater Management that has been pre-filled with the appropriate filter media. Return the empty cartridge to Stormwater Management, Inc. 11.8b Ultra-Urban Filter with Smart Sponge Smart Sponge is an environmental technology utilized to assist in the conservation of the natural environment and its most precious resources by reducing the negative effects of hydrocarbons, contaminants, and debris that is commonly found in our stormwater runoff. Smart Sponge is a unique molecular structure based on innovative polymer technology that is chemically selective to hydrocarbons. Smart Sponge fully encapsulates recovered oil, resulting in a substantially more effective response that prevents absorbed oil from leaching. Smart Sponge is capable of removing low levels of oil from water, thereby successfully removing sheen and remains buoyant in water, permitting it to remain in place until fully saturated resulting in no wasted product. The Smart Sponge technology allows for less expensive and less problematic handling and disposal of the waste product since its technology transforms liquid oil and other pollutants into a stable solid. The Smart Sponge was designed not to deteriorate in water, allowing for a longer product life. Once oil is absorbed, the Smart Sponge transforms the pollutants into a stable solid for easy recycling or disposal, providing a closed-loop solution to water pollution. The Ultra-Urban Filter with Smart Sponge developed and manufactured by AbTech Industries, is an innovative low-cost BMP that helps meet NPDES requirements with effective filtration, efficient application, and low maintenance. It is a stormwater filter that ensures that the water flowing through the system is properly and completely treated. Page 21

23 This solution is used to treat stormwater runoff for new or retrofitted sites by absorbing oil and grease and capturing trash and sediment. The filter comes in two standard designs; one a modular unit geared toward curb inlet openings, and the other, a single unit designed for typical drop-in catch basin drains. Curb Opening Series With Drain Inlet Series with OPERATION, MAINTENANCE & CHANGE OUT The Ultra Urban Filter should be serviced as needed to remove sediments and debris, according to expected debris accumulation. The sediment and debris can be quickly vacuumed out of the modules through the mouth of the drain with conventional maintenance equipment. For example, a curb inlet with four to five Ultra-Urban Filter modules can be serviced within 10 minutes in typical installations. Under normal operating conditions the entire recyclable Ultra Urban Filter should be replaced every 1 3 years depending on its deployment and the pollutant (hydrocarbon) loading. Catch basin cleaning is an integral part of any comprehensive stormwater management plan where closed drainage systems are present. The frequency with which catch basins are cleaned should be based on the site specific factors, accumulation volume and quality. If a catch basin is located in a residential area with low traffic, good street sweeping, minimal possibility of illegal dumping etc. then cleaning may not be required for several months. However, if it is in an urban area with street sanding during winter, high pedestrian traffic with restaurants (trash etc) and perhaps leaf litter, catch basin cleaning may be required more frequently. AbTech suggests customer initiate a plan for regularly scheduled inspections to determine areas with higher accumulations and/or contaminant potential and base your cleaning program on those site-specific situations. [I.e. maintenance facilities, loading docks, intense vehicular-land-use.] Servicing The service requirements for the Ultra-Urban Filter center around three activities: 1. The condition of the Ultra-Urban Filter unit itself, structural integrity, 2. The quantity of solid material accumulated in the Smart Sponge filtration media, 3. The condition of the Smart Sponge filtration media, whether the hydrocarbon absorption capacity is attained. Most environmental service managers tend to focus upon all three activities when it is tasked with providing the maintenance. Page 22

24 To vacuum out accumulated debris from the Ultra-Urban Filter, you could consider the purchase, renting or hiring of a service entity with a solids vacuum cleaning Vactor unit. These are truck mounted units and may provide you with services such as storm drain maintenance and cleaning. A lower cost option is to purchase, rent trailer or hire mounted portable units. The Vactor units should have sufficient suction to vacuum wet debris, the ability to reduce down to 3 4 inch diameter hose (to fit below safety bars that may run across curb opening applications). It should also come with a pressure washing attachment. In conjunction with the cleaning activities servicing should also consider the ability to weigh the filters, and to coordinate events within inspection activities. This will allow for a physical check of the Ultra-Urban Filter as well as the ability to check the condition of the Smart Sponge. How often do the Ultra-Urban Filters need to be changed? Proper maintenance will prolong the efficiency of the Ultra-Urban Filter. The recommended change-out is therefore a function of the Smart Sponge saturation rate. Since every storm drain is different, the best indicators are by visual inspection (the Smart Sponge filtration media will turn yellow, brown and then black) or by its weight (the filter will increase in weight equal 1-3 times its initial Smart Sponge weight). This corresponds to a maximum 40-pound increase in the CO1414 and maximum 60 pound increase in the weight of the DI2020, excluding sediment, trash and debris. Please contact AbTech for other sizes. In normal deployments the range is from a 1-3 year life cycle. Disposal/Recycling Options Smart Sponge technology transforms liquid hydrocarbons into a stable solid. The handling and disposal of this solid waste is less expansive and less problematic than that of other plastic and organic solvents which will leach and leak hydrocarbons back to the environment. The following waste disposal and resource recovery industries will accept spent Smart Sponge for disposal and/or recycling. Waste to-energy Facilities. A specialized segment of the solid waste industry will use spent Smart Sponge as an alternative fuel in the production of electricity. WTE is acknowledged at the federal level as a renewable energy source under the Federal owner Act, Title IV of the Clean Air Act. WTE is a participant in the Department of Energy s National renewable Energy Program. Landfills. The ability of Smart Sponge to transform liquid hydrocarbons into a solid waste makes for less expensive and easy disposal. Spent Smart Sponge generated from the AbTech laboratories have been classified as a solid waste and are acceptable at Subtitle D Landfills. Footnotes: Generators of Smart Sponge will need to have their waste analyzed, tested, and classified to determine the generators particular waste characteristic. According to testing performed for AbTech Industries, spent Smart Sponge soaked with petroleum hydrocarbons are transferred into solid wastes. AbTech does not take any responsibility for the generator s waste classification for handling, transport and the ultimate disposal or recycling of the waste. The generator must always classify and characterize its own waste. Page 23

25 Spent Smart Sponge generated from the AbTech laboratories with a multitude of liquid petroleum hydrocarbons have passed the EPA Toxicity Characteristic Leachate Procedures and Paint Filter Test. These tests are used in determining the amount of liquid waste and any free liquids present that may be released into the landfill environment. 11.8c HYDROSCREEN Curbstop and Parking Lot Inserts Federal water quality discharge regulations also include the runoff from streets and smaller impervious surfaces where a detention pond is not practical. It is imperative that a functional curb and parking lot insert filtration device be able to function without cleaning after each storm. By utilizing tilted wire wedge wire screen this is possible. 11.8c.1 The device will continue to remove debris, organics and water until the entire vault is filled with debris, only then does the unit need maintenance. Organic rubberizer absorbents are located directly below the screen to insure that the oils will not pass into the storm sewer. Different filter media can also be installed to remove selected contaminants Comments/Additional Information (Additional explanations to maintenance activities, and observations about the UNDERGROUND STORMWATER QUALITY STRUCTURES not covered by the form, are recorded in this section). Page 24