SOIL, GROUNDWATER AND SURFACE WATER PROTECTION AND VAPOR EMISSION CONTROL FOR RETAIL SERVICE STATIONS

Transcription

1 TECHNICAL GUIDANCE NOTES TGN/1.8 SOIL, GROUNDWATER AND SURFACE WATER PROTECTION AND VAPOR EMISSION CONTROL FOR RETAIL SERVICE STATIONS JUNE 2016

2 Contents 1. Introduction Disclaimer Pollution Prevention and Control Objective Scope Availability Legal Framework Soil, Groundwater and Surface Water Protection and Vapour Emission Control General Source Pollution Control Risk Assessment Operations Management Systems and Controls Pollution Incident Response Plan General Spill Response Spill Response Facility with OWS Potential Sources of Emissions during Site Operations General Requirements Storage of Oil Bunding Offset/Direct Fill Pipes Dispensers and Under Dispenser Trays Pipework Overfill Prevention Requirements Page 2

3 Forecourt Surface Quality Inspection, Maintenance and Repair Tank/Pipework Testing Delivery Procedures General Site Drainage Stormwater Systems Operations and Maintenance. 21 General Surface Drainage Maintenance All Facilities Site Simple Stormwater Collection System Oil Water Separator Normal Operation Sampling Leak Detection and Maintenance during Operation Detecting Loss of Product Leak Detection Requirements Leak Detection Systems Vapour Emission Control General Vapour Recovery Investigation of Suspected Releases Decommissioning of Facilities General Best Management Practices Surface Pre-cleaning and Cleaning Pressure Washing Page 3

4 Wastewater Collection Wastewater Disposal Refueling Facilities Vehicle Servicing Uncovered Work Areas Washing and Steam Cleaning Areas Building and Maintenance Works Unloading Areas Materials and Waste Storage Stockpiles Parking Areas Washdown Wastewater Training References Contacts Page 4

5 Acronyms Acronym DOHSS ERC GMW KEBS KS LPG NEMA OWS PIRP PPG SIR SMP SMS SOPs SUDs UST Description Department of Occupational Health and Safety Services Energy Regulatory Commission Ground Monitoring Well Kenya Bureau of Standards Kenya Standard Liquefied Petroleum Gas National Environment Management Authority Oil Water Separator Pollution Incident Response Plan Pollution Prevention Guidelines Statistical Inventory Reconciliation Standard Maintenance Procedures Safety Method Satatement Standard Operating Procedures Sustainable Drainage Systems Underground Storage Tank Page 5

6 Terminology Terminology Change Community Company Compliance Contractor Danger Emission Facilities Groundwater Hazard Hazardous Area Hydrocarbon Incident Kenya Standard Management Managers Occupational Health Description Any modification other than replacement in kind. Those residing near to an operating location/tank truck route to whom our activity is easily detectable either visually, aurally or by another means. It also encompasses key decision makers or those having a significant influence over local opinion for the locality. Company within the meaning of the Cap. 486 of Companies Act Meeting legal, regulatory or company requirements. Any company or individual that is under contract to provide services. Risk to the environment, health, life, person or property of anyone from pollution arising from operation and maintenance of petroleum facilities The episodic or ongoing release of materials to the environment (air, water or land). Physical equipment and/or plant, including large mobile equipment, involved in the performance of affiliate operations. Water that is below the surface of the ground in the saturation zone, i.e. below the water table. A potential source of serious harm to people, property or the environment. An area in which there exists or may exist an atmosphere containing flammable gas or vapor in a concentration capable of ignition Chemical compounds containing carbon and hydrogen which are produced by the refining of crude oil and which are generally used as fuels. A specific event or extended condition that has a significant unwanted and unintended impact on the safety or health of people, on property, on the environment, or on legal/regulatory compliance. Specification or Code of Practice declared by The Standards Council under section 9 of the Standards Act Site management is typically the most senior level of operations management working on site. Personnel with line management or supervisory responsibilities. Process encompassing all activities addressing workplace health hazards and employee health. It includes identification, Page 6

7 Terminology Operation Pathway Petroleum Pollution Incident Pollution Prevention Program Practice Project Quality Recommendations Retail Service Station Risk Risk Assessment Description evaluation, and control of health hazards; monitoring of worker exposures; communication of health hazards knowledge, determination of employees medical fitness to do their work and providing or arranging for medical services necessary for the treatment of occupational illnesses or injuries. Any activity involving the production, manufacture, use, storage or movement of material. Also, the utilization of resources by a unit to produce an output. A route by which the contaminant can reach the receptor Petroleum includes petroleum crude natural gas and any liquid or gas made from petroleum crude, natural gas, coal, schist, shale, peat or any other bituminous substance or from any product of petroleum crude, natural gas and includes condensate A pollution incident is any unauthorized discharge to land, air or water that could cause environmental damage. Examples of pollution incidents at sites include: Fuel drips or spills during refueling vehicles Leaks or spills from fuel tanks Leaks or spills from chemical containers, e.g. cans of paint, cleaning chemicals, contaminated run-off entering a watercourse or drain, an oil or chemical spill Pollution prevention describes activities that reduce the amount of pollution generated by a process. The pollution prevention approach seeks to increase the efficiency of a process, thereby reducing the amount of pollution generated at its source. Although there is wide agreement that source reduction is the preferred strategy, some professionals also use the term pollution prevention to include recycling or reuse. Approved method or means of accomplishing stated tasks. A planned undertaking with a specific objective and defined scope. Includes new construction and additions or revisions to existing facilities. The ability for a product, service or activity to meet or exceed requirements. Potential solutions to findings or observations. Premises where petroleum is stored in bulk in one or more tanks and dispensed to consumers for their own use Risk is a function of the probability of an unwanted incident and the severity of its consequences The process by which a risk analysis is conducted and results used to make decisions, either through relative ranking of risk reduction strategies or through comparison with risk criteria or Page 7

8 Terminology Safety Method Statement Site Source Standard Operating Procedures Standard Street Sustainable Drainage Systems Third Party Underground Storage Tank Description other standards of acceptability. The place where something was, is or is to be located. May be a marketing location, a refinery, gas plant or offshore platform. Substance capable of causing pollution or harm. Standard Operating Procedures are documented series of steps to be carried out in a logical order for a defined operation or in a given situation. A defined product or result. Includes requirements for quality, content, review and conformance with regulations. Way, road, lane, square, court, alley, passage or open space, whether a thoroughfare or not, over which the public have a right of way, and also the roadway and footway over any public bridge, or causeway SUDS are a sequence of water management practices and facilities designed to drain surface water in a manner that will provide a more sustainable approach than what has been the conventional practice of routing run-off through a pipe to a watercourse. A contractor providing services in accordance with specifications, terms and conditions documented by a contract agreement and signed by both parties. Underground Storage Tank for fuel, usually made of steel and installed underground. Capacity usually 10,000 60,000 Litres. Page 8

9 1. Introduction 1.1. These Pollution Prevention Guidelines (PPGs), herein referred to as guidelines, provide straightforward guidance on good practices to prevent releases and pollution of air, soil and water environment, as a result of Petroleum Retail, herein referred to as sites, operations, maintenance and abandonment Each site and potential sources of pollution should be assessed individually and is advised to consult the National Environment Management Authority (NEMA), DOSHS and ERC The PPGs have been produced by the Energy Regulatory Commission (ERC). Contact details can be found at the end of these guidelines. 2. Disclaimer 2.1. The information contained in the PPGs is not intended to be prescriptive, or to preclude the use of new developments, innovative solutions or alternative designs, materials, methods and procedures, so long as such alternatives provide a level of control over pollution appropriate to the risks identified The guidelines are provided for information and while every reasonable care has been taken to ensure the accuracy of its contents, the ERC cannot accept any responsibility for any action taken, or not taken, on the basis of this information. 3. Pollution Prevention and Control 3.1. Hydrocarbons which escape from containment at sites may enter the air and groundwater and soil directly beneath of around its perimeter Petroleum products entering the soil and groundwater will, because of their toxicity have a detrimental or fatal effect on the flora and fauna within the contaminated area. Their dispersion will depend on migration of fuel, water movement, biodegradation and soil absorption The extent and duration of pollution will also depend on the quantity and duration of the product release and any subsequent action These PPGs provide practical guidance to operators of sites in order to minimize the risks to air, soil and water environment. 4. Objective 4.1. The purpose of the PPGs is to minimize the potential for site operations to result in a detrimental impact on air, soil and the water environment, primarily through preventing and containing the loss of product. Page 9

10 4.2. The persons responsible for complying with the guideline might not necessarily possess all the appropriate knowledge and expertise. Therefore, responsible persons are urged, as appropriate, to consult relevant guidance or seek expert advice. 5. Scope 5.1. The PPGs will apply to site operators who have custody or control of sites and are for use in operational and abandoned phases The PPGs are relevant to sites which store petroleum hydrocarbons in USTs and contains advice specifically aimed at the following persons: a. Owners b. Persons involved in the operational management c. Persons involved in the maintenance d. Persons responsible for abandonment 5.3. In these guidelines, the water environment includes both surface water and groundwater. Surface waters include all water courses (rivers, streams, burns and canals), lochs, lakes, and coastal waters. Groundwater is also a valuable natural resource and source of drinking water Groundwater also helps to keep streams, rivers flowing and wetlands replenished with often high quality water during dry weather. 6. Availability 6.1. The PPGs are published by the ERC and will be made available. 7. Legal Framework 7.1. Facilities are required to comply with applicable environmental legislation Petroleum hydrocarbons cause serious pollution Responsible persons allowing hazardous substances to pollute the air, soil and groundwater or surface water risks penalties and significant remediation costs Circumstances can arise whereby sites have been, or could be, abandoned without having been subject to appropriate decommissioning. In some instances, product could remain in USTs. Due to lack of on-going maintenance, and the fact that engineering might not be to modern standards, such sites can present a high risk to groundwater. Former operators or current tenants/landowners can be held responsible for preventing pollution. Page 10

11 8. Soil, Groundwater and Surface Water Protection and Vapour Emission Control General 8.1. The PPGs highlight potential risks to air, soil and the water environment and outline good operational and management practices which should be adopted by sites to eliminate or mitigate risks The release of petroleum hydrocarbons can occur not just from the UST itself but also from ancillary equipment and during the movement of product to and from the UST. Source Pollution Control 8.3. Reducing and, where possible, eliminating sources of pollution are more effective than treating effects downstream Source controls place the responsibility directly on the polluter and simple changes in practice can lead to permanent solutions. Risk Assessment 8.5. Hydrocarbons in USTs represent a hazard source. The release of hydrocarbons into the environment could result in significant detrimental effects on a wide variety of receptors. These receptors could be human (e.g. residents of nearby properties) or environmental (e.g. water quality) The potential impacts onto receptors will depend on the magnitude and properties of the hazard source, the likelihood of loss of product and the sensitivity of the receptor The process whereby potential impacts (or risks) can be identified is called risk assessment The primary means of minimizing the potential for USTs to adversely impact the environment and associated receptors is through control measures to prevent loss of product Page 11

12 8.9. The basic model for assessing environmental risk is to consider the source, pathway and receptor. The primary receptors are the air, soil and water environment. There are likely to be a number of pathways between the source and receptors Once the significant risks have been identified, measures can be taken to prevent detrimental impact. Primary measures would be aimed at preventing the release of product. In some circumstances, secondary measures aimed at removing migration pathways could be justified The risk assessment should consider all the potential pathways by which product could reach the environment The outcome of the risk assessment will indicate the optimum operational control systems required to mitigate the identified risks The risk assessment should not be seen as a once and once only process, but should be re-addressed at regular intervals, and revised to take into account significant changes to the site engineering and operation and alteration to the environmental context of the site The findings of the risk assessment should be used to draw up a risk management action plan. This management plan should include measures to prevent loss of containment and should not rely only on measures to mitigate the impact once losses have occurred In determining risk management measures, preference should always be given, if possible, to risk avoidance rather than risk control. For example, risk avoidance would be the location of activities with a high potential to pollute the environment. Risk control, for example, would involve the use of standards of engineered containment and operating practices The risk management action plan should outline the operational control measures that are required to protect the environment including the most suitable means of checking for spills, leaks and emissions. The action plan should differentiate between risks which warrant immediate attention and those that can form part of a longer term improvement program. Operations Management Systems and Controls Management systems and controls should be developed and correctly implemented as part of risk mitigation One of the main methods of demonstrating that a site is being operated in an environmentally responsible manner would be the incorporation of the operational control procedures and adherence to maintenance programs Significant activities for which the development of operational control procedures should be considered include: a. Product delivery b. Dispensing c. Product volume monitoring d. Regular and one-off maintenance activities Page 12

13 e. Control of visiting contractors f. Staff awareness g. Response to major and minor spillages h. Response to alarms and other indications of leakage An important part of any management system is training. Staff training needs should be identified and up-to-date records kept. 9. Pollution Incident Response Plan General 9.1. In the event of loss of product, or other emergency, the environmental impact will be minimized by prompt and appropriate action Each site should draw up its own Pollution Incident Response Plan (PIRP), building on the findings of the risk assessment As a minimum, a typical PIRP should include the following: a. Details of the plan and procedures for keeping it up to date b. Emergency contact details for site operators c. Emergency contact details for third parties (e.g. Fire Brigade, NEMA, specialist contractors etc) d. Product inventory and site layout plan e. Site drainage plan f. Emergency procedures g. Location of emergency response equipment (e.g. fire extinguishers, absorbents, emergency bunding, temporary fencing etc) h. Location of buried services, including water supply pipes. Spill Response 9.4. Sites should have up-to-date and tested spill response procedures and all employees should know the location of spill response material and equipment and be trained in its use The following are minimum requirements: a. The operator should immediately notify authorities and clean up spills. b. Use absorbents to immediately contain and absorb as much of the spilled product as possible and to prevent spilled material from entering the stormwater collection system. c. A sufficient amount of clean up equipment and supplies should be kept in stock at all times. Page 13

14 d. Keep records of date and time of spill, authorities contacted and staff spoken to, steps taken in spill cleanup and recovery. e. In some cases, a written report will need to be submitted to ERC, NEMA and DOSHS detailing the events. Having all the facts readily available will be helpful in this event. Spill Response Facility with OWS 9.6. For a site that has an OWS, the OWS will be able to retain a certain volume of hydrocarbon when there is little or no water flowing through the system. This capacity will be reduced when the flow of water is high, such as during a storm In the case of a large spill, when this retention capacity may be exceeded, the emergency shut-off valve on the discharge piping should be closed to ensure that oil does not escape into the storm sewer. 10. Potential Sources of Emissions during Site Operations The principal sources of loss of product containment are: a. Leaks from: i. Under dispenser valves and flexible couplings ii. Pipework iii. Tanks and offset fill pipes iv. Faulty OWS operation b. Spills during: i. Vehicle refueling ii. Filling of USTs iii. Unloading delivery tankers c. Emissions from: i. Vents ii. Gauging Hatches iii. Fueling Nozzles iv. Leaks and Spills Page 14

15 11. General Requirements Storage of Oil The oil stocks shall be stored in a UST which is of sufficient strength and structural integrity, and has been installed so as to ensure that it is unlikely to burst or leak in its ordinary use The UST must be situated within a secondary containment system which satisfies the following requirements: a. It must be positioned, or other steps must be taken, so as to minimize the risk of damage by impact so far as is reasonably practicable b. its base and walls must be impermeable to water and oil c. its base and walls must not be penetrated by any valve, pipe or other opening which is used for draining the system d. If any fill pipe, or draw off pipe, penetrates its base or any of its walls, the junctions of the pipe with the base or the walls must be adequately sealed to prevent oil escaping from the system Any valve, filter, sight gauge, vent pipe or other equipment ancillary to the UST (other than a fill pipe or draw off pipe or a pump) must be situated within the secondary containment system If the connection point to a fill pipe is not within the secondary containment system, a drip tray must be used to catch any oil spilled when the UST is being filled with oil For USTs, any fill pipe, draw off pipe or overflow pipe must be positioned or other steps must be taken, so as to minimize any risk of damage by impact so far as is reasonably practicable and: a. Have no mechanical joints, except at a place where it is accessible for inspection by removing a hatch or cover b. Adequately protected from physical damage c. Adequate facilities for detecting leaks d. If fitted with a leakage detection device to continuously monitor leaks, the device must be maintained in working order and tested at appropriate intervals to ensure that it works properly e. If not fitted with a leakage detection device, must be tested for leaks before it is first used and further tests for leaks must be performed in the case of pipes which have mechanical joints f. If made of materials which are liable to corrosion, it must be adequately protected against corrosion, and pipes permeable to hydrocarbon vapors must not be used Page 15

16 11.6. The UST must be fitted with an automatic overfill prevention device (which may include an alarm sounding device) if the filling operation is controlled from a place where it is not reasonably practicable to observe the tank or vent pipe The tank must be filled via a screwed fitting or other fixed coupling which is in good condition. A drip tray must be provided at the time of fuel delivery to catch any oil that could be lost during the coupling and decoupling of the delivery hose Where oil from the tank is delivered through a flexible pipe which is permanently attached to the container or delivery pump: a. The pipe must be fitted with a tap or valve at the delivery end which closes automatically when not in use b. The tap or valve must not be capable of being fixed in the open position unless the pipe is fitted with an automatic shut off device c. The pipe must be enclosed in a secure cabinet which is locked shut when not in use and is equipped with a drip tray, or the pipe must have a lockable valve where it leaves the container which is locked shut when not in use and be kept within the secondary containment system when not in use Any pump must be: a. fitted with a non return valve in its feed line b. positioned or other steps must be taken, so as to minimize risk of damage so far as is reasonably possible c. protected from unauthorized use Any permanent vent pipe, tap or valve through which oil can be discharged from the tank to the open must satisfy the following requirements: a. it must be situated within the secondary containment system b. it must be arranged so that oil discharged from the tank other than to its intended destination is contained within the system c. In the case of a tap or valve, it must be fitted with a lock and locked shut when not in use Where a drum is used for the storage of used oil in conjunction with a drip tray as a secondary containment system, it is sufficient if the tray has a capacity of not less than 25% of: a. the drum's storage capacity b. If there is more than one drum used at the same time with the tray, the aggregate storage capacity of the drums. c. Where oil is delivered through a flexible pipe which is permanently attached to the unit, the pipe must be fitted with a manually operated pump or with a valve at the delivery end which closes automatically when not in use. d. When the pipe or valve is not in use they must be locked shut and in the case of the pipe, be fitted with a lockable valve at the end where it leaves the container For UST the following requirements must be satisfied: Page 16

17 a. Tanks will be constructed from steel; glass reinforced plastic (GRP) or using a combination of steel and plastic. They may be single or double skinned depending on the type, construction and intended use. b. Any corroded or defective tank should be taken out of use. c. Corrosion control should be provided by cathodic protection and a method provided to confirm the continued effectiveness of the system. The most effective corrosion protection is provided when high quality coatings and an appropriate cathodic protection system are used in combination. d. A detailed inspection and assessment by a competent person will determine whether a defective tank can be repaired or should be replaced. All repaired tanks should be leak tested before being brought back into service. e. USTs which are not going to be used should be removed where possible. Where USTs are abandoned in-situ they should be purged and filled with hydrophobic foam. Where USTs are filled with water to make them safe on temporary basis, the water level should be checked on regular basis. Tanks should not be permanent filled with water Storage of oil in petroleum retail sites shall be in USTs in accordance with KS1969 and KS2506 and shall not be in drums or other portable containers. Bunding New oil storage tanks must be provided with secondary containment (bunding). This can be achieved by installing an integrally bunded oil storage tank or by constructing a concrete or masonry bund The base or wall of a bund must not be penetrated by any valves, pipes or other openings which could be used for draining the bund If a fill pipe or draw-off pipe penetrates the base or wall of the bund the junction of the pipe must be adequately sealed to prevent oil escaping from the bund (steel fabricated puddle flanges are recommended for this use). Offset/Direct Fill Pipes Below ground offset or direct fill tank man chambers are prone to the accumulation of small amounts of product during delivery If such man chambers appear oily on the surface of the walls, but do not accumulate significant product, then the walls may be leaking and require remedial work. Dispensers and Under Dispenser Trays Dispenser leaks are the most common containment failure at sites It is recommended that all dispensers be fitted with a leak proof drip tray or membrane arrangement beneath the dispenser. Page 17

18 With pressure system, leak proof sumps may be used instead of or in addition to drip trays All installations should be inspected for integrity every six months. Pipework Underground pipework serving an installation must be protected from physical damage and should also incorporate a leak detecting facility The use of non-metallic pipework and better protection available for steel pipework together with secondary containment techniques have reduced incidents of soil and groundwater contamination If this is not achievable then the pipes must be pressure tested and the result recorded before they are first used and then again once every ten years if there are no joints and once every five years if there are joints All joints in underground pipework must be accessible for inspection and maintenance. The methods of testing pipework will be determined by the type of pipework, its installation and the risks involved The removal of pipework can only commence after a risk assessment and the pipework drained and isolated from fuel sources. Overfill Prevention Requirements An owner/operator shall ensure that releases from overfills do not occur. Transfer of stored substance may not exceed the volume available in the receiving tank and the transfer shall be adequately monitored Immediate action shall be taken to stop the flow of regulated substance prior to exceeding tank capacity or in the event that an equipment failure occurs Tanks must be installed with the following: a. A gauge or monitoring device which accurately indicates the level or volume in the tank and is visible to the individual responsible for the transfer of product. b. The monitoring device shall be installed, calibrated and maintained in accordance with manufacturer s specifications. c. A high-level alarm with an automatic high-level cut-off device or a high-level alarm with a manned operator shutdown procedure in operation. Forecourt Surface Quality Areas susceptible to contamination should be impermeable to hydrocarbons and other liquids and should not allow seepage through or below the surface Hardstanding areas do not remain impermeable over a long period of timeand can be compromised by pipework repair, subsidence or wear and tear along pavement expansion joints. Page 18

19 Inspection, Maintenance and Repair Factors to be considered in assessing the risk to air, soil and water environment that could occur during maintenance and repair activities include: a. Sufficient draining of pipelines/tanks to minimize the potential for fuel spills to the environment prior to repair works. b. Procedures in place to avoid accidental damage to tanks and associated pipe work during maintenance works c. Procedures and materials in place to deal with any small spillages that occur d. Monitoring and checks in place to ensure that all repairs have been performed to a satisfactory standard e. Contractors undertaking maintenance work should be properly trained/equipped to undertake the tasks f. Materials (including waste waters) containing waste fuels, which arise during the course of repair works will be disposed of to suitably licensed waste disposal facility SMS and SMP will ensure that the work is properly planned and that all changes are adequately documented. Tank/Pipework Testing Where a leak is suspected the tank/or pipework should be tested using an appropriate method for the installation. The tank testing system should detect a leak of 380 ml/hour or more with 95% probability Tests generally fall into two broad categories: a. Volumetric Method b. Non-volumetric Method SMS and operating protocols should always be available with test methods. 12. Delivery Procedures General Delivery procedures should include USTs ullage checks to avoid the possibility of tank overfills Overfill contingency plans should be based upon product dispensing to avoid the risk of spills. Site Supervise all deliveries to USTs to help avoid spillages. Page 19

20 12.4. Agree with the oil delivery company on safe delivery and emergency procedures Position a notice giving details on safe delivery procedures and what to do in an emergency at the delivery point Locate fill pipes within the confines of the secondary containment system. Fit a shut-off valve to extended fill pipes because they may retain oil following the delivery Ensure that fill pipes have a 50 mm diameter threaded connection, a lockable fill cap with a chain and are marked clearly with the product type, tank capacity and tank number Where a fill pipe is outside the containment system, use a drip trayof an adequate capacity to contain the contents of the fill pipe and to catch any oil spilled during delivery. Put this drip tray in a cabinet that can be locked when not in use to protect it from vandalism and rainwater damage Check the drip tray after each delivery and empty it if it contains any oil. If available, use a serviceable screw fitting or other fixed coupling when filling the tank If a screw fittingor other fixed couplingis fitted to the tank, you must maintain it in good condition, and use it when filling the tank If you use a permanently attached, flexible pipe to deliver oil from the tank to a container or delivery pump, you must: a. fit a tap or valve at the delivery end of the pipe, which closes automatically when not in use b. Ensure that the tap or valve cannot be fixed in the open position, unless the pipe is fitted with an automatic shut-off device When a delivery pipe is not in use you must ensure that it is kept in a secure, locked cabinet with a drip tray, or has a lockable valve (locked shut when not in use) where it leaves the container. Drainage All surfaces where contamination is possible and drainage apparatus which could receive contaminated water should be contained by peripheral surface drainage channels to divert all spills and run off to an oil/water separator Surface drainage requires the separation and the removal of silt, grit and pollutants Wastewater drainage requires the separation and removal of oil, fat, grease and volatile substances Factors to assess the risk to soil and the water environment arising from on-site surface water drainage systems include: a. Age and condition of the drainage system b. Integrity of the drainage and effectiveness in dealing with fuel spills c. Drainage routing on the site Page 20

21 d. Location of discharge of waste materials/effluents by the site e. Existence of soakaways on-site f. Cleanliness and function of the forecourt oil/water separator g. Location of discharge of oil/water separator from site h. Appropriate dispensing and monitoring procedures employed i. Linkage between drains and receptors j. Vehicle washing facilities drain through a separate dedicated system All drainage channels and systems should be installed and maintained according to manufacturer s instructions. 13. Stormwater Systems Operations and Maintenance General Fuels are lighter than water and will float when not disturbed At some petroleum sites, particularly those that transfer higher flow rates and volumes of fuels, this property is used to contain spilled fuel in OWSs. Surface Drainage Maintenance All Facilities Prevent pollutants from mixing with stormwater runoff by: a. Either wiping up spills with rags or cleaning up any spills with sorbents. b. Never hose down spills with water unless there is an oil/water separator to capture runoff. c. Never pour wastes into drains, onto the ground, or into an OWS. d. Never clean paved areas with a hose and water unless there is an oil-water separator to capture runoff. Sweep with a broom instead. e. Pick up any litter on the lot and dispose of in trash to prevent the litter getting into the stormwater drains and potentially clogging them Daily inspect for evidence of spills that may have happened, If evidence of a recent spill is discovered, inspect the surrounding stormwater collection system to determine if product migrated into the catch basins or OWS Fuelling areas have a concrete surface that is impervious to hydrocarbons and allows most spills to be contained. Repair and replacement of cracked or otherwise damaged paved areas is recommended if the damage could lead to product escaping to the environment. Page 21

22 Site Simple Stormwater Collection System At many sites, stormwater runs off into the municipal storm water collection system At other sites, there is a collection system consisting of catch basins and manholes which are then connected to the nearby municipal system Catch basins and manholes on the property should be inspected annually and accumulated sludge and debris removed A clean out is typically done by a sewer maintenance company using a vacuum truck. 14. Oil Water Separator Normal Operation Most separators are equipped with a shut-off valve at the outlet which can be closed in the event of a spill to isolate the contents of the tank until a licensed hauler can attend at the site to pump out the spilled material for disposal Some sites also have a valve on the inlet piping that is used to isolate the vessel for safety in the event that it needs to be entered into for maintenance purposes The inlet valve should normally be left open while the outlet valve is normally left closed. They should be labeled with open and closed positions, or otherwise readily identifiable to help prevent them from being left in the wrong position. Another option is to post a schematic nearby that details valve operation Oil collecting in the separator is skimmed and routed to a separate tank for storage and subsequent disposal in accordance with Waste Management Regulations Staff should be familiar with the system and know which catchbasins are connected to the separator. Sampling There are regulatory legislative requirements that require effluent from the oil/water separator to be sampled and analyzed by NEMA accredited laboratory at a certain frequency in accordance with Water Quality Regulations It is a site operator s responsibility to be in compliance with the environmental legislative requirements in his/her jurisdiction The laboratory normally supplies jars or bottles for collecting the samples. They may also supply instructions for handling or taking samples. Samples should be kept cool and shipped to the laboratory as soon as possible Laboratory results should be kept with other records and logs and submitted to NEMA in accordance with Water Quality Regulations. Page 22

23 15. Leak Detection and Maintenance during Operation Detecting Loss of Product Methods for detecting loss of product include leak detection systems and wetstock monitoring, environmental monitoring and integrity testing On-going automatic leak detection without loss of product is only possible with double skinned equipment; this should provide warning of failure prior to release of product to ground Wetstock monitoring has taken various forms ranging from Statistical Inventory Reconciliation (SIR) to manual monitoring using a dipstick. Whilst wetstock monitoring will not detect a leak before product is lost to ground, the more sophisticated systems should provide a relatively rapid indication (i.e. within days) that a leak is occurring Besides visual inspection of surface drainage and interceptors, environmental monitoring utilizes boreholes to monitor for the presence of vapors, dissolved product or free phase product in the ground Leakage will only be detected at a late stage once product has migrated through the ground and reached the boreholes. Depending on the location of the boreholes and the sensitivity and frequency of monitoring, leakage might have been ongoing for a relatively lengthy period (i.e. weeks) before being detected by this method There is a risk that, if not located properly, the boreholes could fail to detect a contamination plume. It must be remembered that the boreholes themselves can act as preferential pathways for the migration of pollution into an underlying aquifer To ensure that any near-surface contamination is not transferred to any deeper aquifers, appropriate methodologies should be used when drilling boreholes. Page 23

24 15.8. Integrity testing based on pressurizing tanks and pipework to detect any leaks or faults is usually carried out before a site is brought into service. Thereafter integrity testing based on precision tank or line tests is only normally carried out in support of a monitoring system or if a leak is suspected. Integrity testing could include the use of environmental tracers. If integrity testing alone is used to monitor for loss of product, leakage could be on-going for very long periods (i.e. years or decades) before being detected Overall, based on effectiveness, the preferred hierarchy for detecting the loss of product is as follows: effectiveness a. Automatic Leak Detection Systems b. Wetstock Monitoring c. Environmental Monitoring d. Integrity Testing Leak Detection Requirements Site operators should dip their USTs for accumulated water content on a daily basis: a. The presence of water in a tank can occur from condensation of water vapor,- surface water run-off entering the fill-pipe. b. If water is detected in USTs to a depth of 5 cm. or more, the operator should contact his supplying company and report water content. c. The services of an approved petroleum equipment maintenance contractor should be engaged to pump out the water contaminant. d. Small quantities of contaminated water (up to 100 Litres) may be placed in the used-oil storage tank. This practice should be minimized in keeping with the recommendations for used oil. e. Quantities in excess of 100 Litres will be collected intanks or drums and transported to a marketing terminal for treatment in a gravity separator. f. Contaminated water from USTs must NOT be discharged into the site oilwater interceptor, or to the storm sewer. The contaminated water may not be sent to a sanitary sewer unless it meets the specifications in the municipal sewer use by-laws and any other applicable municipal requirements. g. It is a primary requirement that site operators will maintain the fill-box and fill-cap on all USTs to minimize water contamination from surface run-off. h. All underground lines must be annually leak tested. There are several methods to choose from, including tracer gas, hydrostatic, lockdown pressure, or double-walled piping with sump sensor and audible alarm. i. Equipment that is used for release detection, monitoring or warning must be maintained in good working order. Equipment must be checked at least yearly or in accordance with the manufacturer s guidance to ensure it is calibrated and working properly. Page 24

25 Leak Detection Systems The accuracy of stock monitoring and other leak detection techniques is critical to detecting leaks at an early stage Poorly maintained leak detection systems are severely impaired in performance. Leak detection standards vary according to the method An effective leak detection system provides an early warning of a potential problem to enable prompt corrective action to be taken. METHOD OPERATION OF Monitors air pressure or vacuum between the skins. Alarms if pressure changes Monitors pressure of a liquid filling the gap between the skins. Detects the presence of liquid or hydrocarbon vapor with the interstitial space Analyses, compares or monitors rate of change of tank contents Use monitoring wells round the site to detect released product Changes in tank and metered sales manually are reconciled DETECTION CAPABILITY Detects leaks anywhere in double skin equipment irrespective of product level Detects leaks anywhere in double skin equipment irrespective of product level Detects leaks in double skin equipment with large interstitial space Detects leaks in tanks and pipework Detects leaks below the liquid surface level in tanks and pipework Detects leaks in tanks and pipework EFFECTIVENESS Very secure system. Alarms before product can reach the environment Very secure system. Alarms on any leak. External leak loses fluid into the ground Liquid sensors at low points. Vapor sensors unable to detect failure of outer skin Product released to the environment before a leak is detected Product released to the environment before a leak is detected Product released to the environment before a leak is detected The choice of the leak detection system will depend upon the circumstances of a site and its surrounding environment. a. Appropriate operational controls include: i. General operational control procedures ii. Leak detection and environmental monitoring iii. Maintenance b. The main types of leak detection and wetstock monitoring systems can be split into a number of classes numbered from 1 to 7, with decreasing effectiveness. c. The operation and effectiveness of these systems are summarized below. Page 25

26 CLASS EQUIPMENT MONITORED METHOD OPERATION 1, 2 & 3 Tanks and pipework Monitor interstitial spaces in double skin equipment 4a Tanks and pipework Analyses change in tank contents with volume dispensed (automatic monitoring) 4b(1) & 4b(2) Tanks Analyses rates of change in tank contents (automatic monitoring) 5 Tanks and pipework Monitoring wells around storage area 6 Tanks and pipework Manual monitoring of product volumes and sales 7 Pipework Measures pressure in pipework EFFECTIVENESS Indicates failure before loss of product to environment Leak is not detected until product is lost to environment Leak is not detected until product is lost to environment Leak is not detected until product is lost to environment Leak is not detected until product is lost to environment Leak is not detected until product is lost to environment It should be noted that the most effective systems, i.e. those which detect a failure before loss of product into the soil, can only be used in conjunction with double skinned systems. 16. Vapour Emission Control General Quote OSHA and EMCA requirements Release of product from the site to the air will either be through vents, fueling nozzles, dip tubes or pipework maintenance and may be planned during maintenance or calibration or unplanned through leaks and spills. Vapour Recovery With vapor control equipment the vapor vents from the UST are connected back to the delivery tanker. To stop the vapor going out to the atmosphere, the tank vents are fitted with pressure vacuum valves which maintain a small back pressure in the system that with the negative pressure in the delivery tanker ensures that vapors flow back to the vehicle compartment. Page 26

27 16.4. High emission control efficiencies can only be achieved if the system is correctly designed with particular attention to component selection and installation All changes to an existing installation may require changes, which should be noted on site drawings, on new pipework and in chambers. Investigation of Suspected Releases The owner or operator of the site shall initiate and complete an investigation of an indication of a release of a regulated substance as soon as practicable after the indication of a release An indication of a release includes one or more of the following conditions: a. The presence of unusual level of vapors from the site. b. Evidence of vapors in soils, basements, sewer lines, utility lines, surface water or groundwater in the surrounding area. c. Unusual operating conditions such as the erratic behavior of product dispensing equipment. d. The sudden or unexpected loss of product from UST or the unexplained presence of water in USTs. e. Test, sampling or monitoring results from a release detection method which indicate a release. f. The discovery of holes in USTs during activities such as inspection, repair or removal from service. g. Other events, conditions or results which may indicate a release The investigation shall be sufficiently detailed to confirm whether a release of product has occurred. The owner or operator shall investigate the indication of a release by one or more of the following procedures: a. Check product dispensing or other similar equipment. b. Check release detection monitoring devices. c. Check inventory records to detect discrepancies. d. Testing of USTs for tightness or structural soundness. e. Sampling and analysis of soil or groundwater. f. Other investigation procedures which may be necessary to determine whether a release of a regulated substance has occurred The owner or operator shall take necessary corrective actions to completely stop product releases If the investigation confirms that a release has not occurred, further investigation by the owner or operator is not required. Page 27

28 17. Decommissioning of Facilities General Factors to be considered in decommissioning sites: a. Decommissioning methods will not result in the release of product to the ground b. Product released discharges to the sewage network c. Below ground equipment remains after decommissioning d. Decommissioning methods result in product remaining in-situ in below ground structures (tanks, pipework, drainage) During the decommissioning of sites, product could be lost to ground as a result of either deliberate or accidental release during dismantling and removal of USTs and pipework. In addition, a risk could arise off-site if contaminated USTs and pipework are not disposed of in an appropriate manner It would be preferable to remove all redundant USTs and pipework. If USTs are left in-situ, a risk could arise if any residual product remains in the USTs. As the integrity of the equipment would no longer be maintained or monitored, the potential risk posed might be greater than during the operational lifetime of the site. There should be no connection or pathway between decommissioned USTs or pipework and the sewage network Residual product should be removed from USTs. This process is known as bottoming. Care must be taken to ensure that no product is lost to ground. All USTs must be bottomed and made safe before removal from the ground. Similar methods should be employed prior to removal of pipework Once removed from the ground all USTs and pipework should be made safe for transport, e.g. by cold cutting to allow free venting If water is used during bottoming, it must be removed prior to transport. As the water will be contaminated with the residual product, a risk of contamination of the water environment could arise if it is not disposed of in a manner appropriate to the degree of hydrocarbon contamination. Typically this would involve consignment to a suitable waste treatment facility If USTs are being left in-situ, they must be made safe. Following bottoming and making safe, tanks should be filled with either: a. a sand and cement slurry b. hydrophobic foam c. Foamed concrete Wherever practicable, oil/water separators should be removed for off-site disposal. Otherwise they should be filled in a similar manner to USTs. Regardless of the fate of the oil/water interceptor, all residual liquid and sludge should be removed (for off-site disposal) and all inlet and outlets should be sealed. Page 28