A field guide to oil spill response on freshwater shorelines: chapter 9

Each of the following freshwater oil spill responses are described using the following sections:

• Incident Summary
• Challenges Identified
• Lessons Learned and Best Management Practices

Section 9.3 provides an overview of key lessons learned from these various freshwater oil spill responses.

9.1 Canadian freshwater oil spill response

9.1.1 Case studies: freshwater spills - NePCO 140, The St. Lawrence River (1976)

Incident summary

• The tank barge NEPCO 140 on route from Murray Bay, Canada to Oswego, New York, USA, with a cargo of 17.1 million L of No. 6 fuel oil grounded on Wellesley Island in the American Narrows section of the St. Lawrence River on June 23, 1976.
• An estimated 1,167,000 L of oil were reported lost before operations to secure the discharge were completed.
• Water levels were high when the spill occurred – the high water and swift current carried the oil downstream at a rapid rate.
• The oil spread 137 km downstream and contaminated more than 482 km of island and mainland shoreline.
• Due to river currents of 2-7 knots and prevailing westerly winds, the oil contaminated an intricate network of bays, inlets, and islands.

Challenges identified

• Boom deployment to limit downstream movement of oil was ineffective due to wind, current, and channel depth and width.
• Inability to mitigate damage resulted in a time consuming and expensive treatment and contamination of highly developed residential areas (e.g. Alexandria Bay, New York), wilderness shoreline, wildlife refuges, and very productive marshes.
• Due to the large geographical area affected, the On-Scene Commander (OSC) could not adequately direct treatment in all areas in a timely manner.

Lessons learned and best management practices

• Creation of sub-areas controlled by a specific individual (on behalf of the OSC) and supported by treatment supervisors who directed contractor activities.
• Need to reduce the affected area through planning and preparation for an incident of this nature (i.e. need to consider a variety of plausible difficulties as part of preparedness planning efforts).
• Documentation is necessary for future reference and to make more knowledgeable daily decisions (e.g. create a master log for the spill where all major daily events are recorded).
• Establish a centralized point for communications with the public.
• Contingency planning should consider expected oil behaviour in various geographical locations (e.g. water depth, current patterns, tides, seasonal conditions) to gain a better understanding of how a specific product will behave in given conditions and allow for pre-establishment of control points or recovery sites.
• Following the spill, there was confusion with respect to what the effects of such a large spill would be in a riverine environment – there was very little documentation to answer questions posed by the public and scientists.
• Highlighted the importance of funding and conducting research regarding oil spill related effects in non-marine environments.

9.1.2. Case studies: freshwater spills - Pine River, BC (2000)

Incident summary

• On August 1, 2000, a pipeline transporting sour light crude (BC Light) from Taylor to Kamloops in northern BC ruptured, spilling approx. 985 m³ (6200 bbls).
• The incident occurred on the Pine River, approx. 110 km upstream of the community of Chetwynd – the Pine River flows into the Peace River.
• The environmental effects included mortality to fish, insects, and some wildlife – estimates of potential fish mortalities as a result of the spill ranged from 15,000 to 250,000.
• The river water supply to the District of Chetwynd was shut off and the use of many groundwater wells near the river was discontinued.
• Product recovery was high: 450 m³ removed from the river; 415 m³ removed in contaminated soil; and approx. 80 m³ spread throughout the environment.
• The unaccounted-for amount was estimated to include volumes dissolved in the water, absorbed in the sediments of the river’s banks and bed, and trapped in backwaters, eddies and log jams.

Challenges identified

• The Pine River is a high-flow body of water – oil was stranded at a high-water mark and there was a sense from the public that not enough was done to recover oiled materials before a rain event or winter and subsequent freshet.
• Lack of consensus with respect to treatment of oiled woody material on the shoreline (i.e. oiled log jams) options discussed were treat, burn, remove, or leave in place.
• Closure of the recreational fishery in the area took several days and the process to do so was not clear.

Lessons learned and best management practices

• Fish kills in moderate-size rivers can extend far downstream if the spill is not contained quickly.
• Implementation of a SCAT program would have provided information to address extent and nature of shoreline oiling and improved communications with the public.
• Formation of a Treatment Advisory Group (TAG) with representation from various agencies (including biologists, scientists, and managers), First Nation, and responsible party may have helped to focus discussions and reach a decision(s) with respect to treatment of oiled woody material – regulatory authorities of agencies involved also needed to be clearly understood.
• River booming was successfully implemented at 22 km and 30 km downstream of the ruptured pipeline and this minimized the downstream extent of shoreline oiling.

9.1.3 Case studies: freshwater spills - Mystery Spill/land Based, used Oil, Rouge River into Detroit River, ON (2002)

Incident summary

• Following a heavy rain event, a mixture of diesel fuel and lube waste oil was observed on April 9, 2002, in the Rouge River. Another heavy rainfall on April 12, 2002 caused a second oil spill.
• It appeared the oil came from one of the combined sewer outfalls on the Rouge River (Baby Creek Outfall). This release was trapped in the Rouge River due to booming at the mouth, preventing further releases of oil into the Detroit River.
  • Estimated 115,000 to 230,000 L of oil spilled.
• Oil released affected approximately 27 km of shoreline in the USA and almost 16 km on the Canadian side of the Detroit River, including approximately 1.6 km of shoreline at the Lake Erie Metropark where oiled marsh vegetation was cut and removed.

Challenges identified

• The ice had only recently receded, and water temperatures were still quite cold even with warmer air temperatures.
• Limited shoreline access by boat, shallow water around the affected islands, often with steep rocky shorelines posed challenges for response efforts.
• Identifying the source of the spill was a challenge with many kilometers of sewers and storm drains; some dating back decades with few existing plans.
• Significant historic oiling along the shoreline made it difficult to determine if treatment was being done for recent spill.
• Spilled product analysis identified arsenic, lead, and other hazards that required higher levels of PPE.
• The shoreline of the river had a significant number of rusty/used syringes (medical waste) in the area being treated.

Lessons learned and best management practices

• The United States of America and Canada joint contingency plan was invoked and Canadian Coast Guard (CCG) acting as on scene command called on ECRC as response contractor.
• ECRC provided the equipment and personnel to treat areas identified by REET (now the Science Table), under daily work orders with CCG.

9.1.4 Case studies: freshwater spills - Lake Wabamun, AB (2005)

Incident summary

• A derailment of train cars at 05:20 MST on August 3, 2005 occurred adjacent to Lake Wabamun, approximately 60 km west of Edmonton, Alberta, Canada.
• Of the 46 rail cars that derailed, 25 were carrying ‘Bunker C’ and one was ‘Imperial pole treating oil’ (PTO).
• Eleven cars lost all or part of their loads of Bunker C (total spill volume of approximately 712,000 L):
  • 320,000 L recovered as free liquid oil;
  • 231,500 L removed in contaminated soil;
  • 160,500 L unaccounted for (e.g. absorbent, shoreline, emergent aquatic vegetation).
• The PTO car lost approx. 88,000 L of product with some recovery from soil and groundwater.
• Bunker C was heated and placed inside insulated tanker cars for transport; this affected the product viscosity and it was able to flow into the lake within a few hours of the derailment.
• The lake had a high profile at the time of the incident due to the variety of surrounding land uses (agriculture; forested areas; two surface coal mines supporting three coal-fired power plants; permanent residences; recreation – provincial park and cottages).

Challenges identified

• Sensitivity mapping exercise had not previously been completed for this waterbody; as sensitivities were not documented, setting of priorities for shoreline treatment was problematic.
• Emergent vegetation beds had trapped oil and were acting as a reservoir for oil remobilization.
• Concerns with cutting oiled emergent vegetation potentially affecting the recovery of beds.
• Submerged and sunken oil was identified as a potential issue early in the response.

Lessons learned and best management practices

• Oil behaviour was unique due to the rapidity at which tar balls formed:
  • Likely related to the uptake of materials (e.g. grass, insects, sediments, coal particles) by the heated oil as it flowed overland before entering the lake;
  • Continued entrainment of material once in the lake;
  • Most submerged/sunken oil was in shallow, nearshore waters.
• Oil was observed to re-surface:
  • Loss of solid matter by break up, sloughing of surface, loss of heavier entrained material (e.g. sand), and density changes due to temperature changes in the lake (particularly in the shallow, nearshore water that more readily undergoes heating/cooling throughout day/night) and in the oil.
• A Treatment Advisory Group (TAG) was formed in response to challenges.
• TAG was chaired by Alberta Environment and Environment Canada, and included membership from residents, First Nation, Provincial, and Federal partners, and the responsible party (RP).
• TAG provided review and guidance with respect to:
  • Site-specific treatment plans for ‘Very Sensitive Areas’ (e.g. large emergent vegetation beds; segments adjacent to fish spawning habitat);
  • Shoreline areas covered under the general shoreline treatment plan that required a type of specialized treatment, i.e. areas that presented challenges for treatment teams (e.g. oiled beaver lodge).
• Led to improved understanding among stakeholders of feasibility and success of shoreline treatment.

9.1.5 Case studies: freshwater spills - Charette, QC (2006)

Incident summary

• On June 4, 2006, a train derailment of 14 cars containing chemicals (sulphuric acid) and light petroleum products (gasoline and diesel) occurred at the junction of a railway bridge crossing the rivière du Loup near the town of Charrette, QC.
• Approximately 110,000 L of gasoline and 122,000 L of diesel were spilled and contaminated soils adjacent to the track and near the river. An undetermined quantity of hydrocarbons reached the rivière du Loup by percolation through the ground as well as an overflow of water pits following heavy precipitation.
• An artificial lake dam (Chute-à-Magnan) facilitated the deployment of a boom in calm water near the site.
• A SCAT survey was conducted of the sector downstream of the river. No contamination was found on the banks. However, oil contamination was observed on the water in areas where organic material accumulated.

Challenges identified

• River flow was transporting oil downstream towards a populated area (Louisville) and Lac St-Pierre which is a UNESCO Biosphere reserve (migratory birds and vast areas of marshes).
• There was very little access to the upper and mid parts of the river.
• In addition, the significant vertical drop in the upper section of the river limited the number of effective boom deployments.

Lessons learned and best management practices

• Initiate early communication with population on risks related to the presence of hydrocarbon odours.
• Considering variations in water levels in the river, the booms were initially deployed at access points where the river slope was low.
• The containment booms were first deployed at the most downstream section of the river and then subsequent deployments were conducted further upstream.
• Since the spilled hydrocarbons were light refined products, effects on the environment were minimal and of short-term duration.
• Lack of communication between “environment” people and “operation” people resulted in unexpected delays during the initial response phase.
• Identification in advance of spill control points would have sped up response and prevented further oil migration.
• Plan for communications where cellular and data coverage is unreliable.

9.1.6 Case studies: freshwater spills - Lac-Mégantic, QC (2013)

Incident summary

• On July 6, 2013 a train of 72 cars carrying 7.7 million L of crude oil derailed in downtown Lac-Mégantic, QC. A fire ensued causing multiple explosions as well as the emission and discharge of petroleum products into the environment. Approximately 1.57 million L of petroleum remained contained in the cars.
• Of the approximately 6 million L spilled or burned, it was estimated that 300,000 L of light bakken crude oil reached the Chaudière River, whose head flows from Lake Mégantic.
• The Chaudière River is the source of drinking water for three municipalities and two agro-food industries.
• The water levels of Lake Mégantic are controlled by a dam at the head of the river. It was closed during the first hours of the operation, causing variations in the water level of the river.
• The oil spilled indirectly into the Chaudière River through Lake Mégantic and directly by travelling through municipal drains.
• The Chaudière River is 185 km long and has a steep drop in its upper portion (2.5 m per km).
• Series of booms were installed at 14 different strategic points along the river.

Challenges identified

• Exposure to heat and to the flame retardant used to fight the fire affected the physicochemical properties of some of the hydrocarbons discharged into the river.
• Shoreline vegetation was burned by the product and turned yellow.
• Fluctuating water levels and high-water turbulence dispersed the hydrocarbons in the water column, which resulted in some of the oil accumulating within the coarse sediments of the river bed. As such, these light hydrocarbons had a longer environmental persistence than if exposed to the air.
• Identifying access points to the river and the owners of land whose shorelines were oiled was a challenge – due to thick shoreline vegetation, SCAT was conducted on foot in the shallow nearshore water.

Lessons learned and best management practices

• Shorelines were assessed for oiling using SCAT and treatment recommendations provided. Precise segmentation of the river’s shoreline was done using kilometre points from the source of the spill.
• Specific surveys to locate oil trapped in river bed sediments were made in parallel with the river bank SCAT surveys. More than 40 transects were investigated to establish the extent and locations of the contamination.
• The initial treatment of the river was carried out in two phases:
  • Shoreline treatment using manual recovery methods.
  • Agitation of oiled river bed sediments through deluge and manual wet tilling.
• The deluge and wet tilling treatment methods were effective for coarse sediments.
• Sensitization of and consultations with the river bank property owners were paramount to reaching the work sites along the river.

9.1.7 Case studies: freshwater spills - Cheecham Pipeline, AB (2013)

Incident summary

• Incident occurred on June 22, 2013 in northern AB, Canada.
• The source was a pipeline located 70 km southeast of Fort McMurray between Anzac and Janvier.
• Approximately 750 bbls (119,240 L) of synthetic crude oil released from a pipeline failure following land movement due to unusually heavy rainfall in the region.
• Oil flowed downslope through a fen/wetland area and then into an unnamed lake south of Fort McMurray.

Challenges identified

• Heavy rainfall continued to challenge workers at the site. Access and site conditions were difficult. Access was by foot, all-terrain vehicle and helicopter.
• Health and safety issues included: access; soft substrate; and vapours.
• Needed a new contamination survey methodology as site was not linear (small length of shoreline).
• Very sensitive environment with very limited oil movement due to <5% slope.

Lessons learned and best management practices

• Limiting the effects on sensitive fen/wetland habitat through use of boardwalks.
• Used systematic spot flushing combined with general flushing.
• High capacity pumps required as the limited slope prevented oil movement. High volume of water needed to move oil towards collection points. Nearby lake used as a water source, but water level monitor required at all times to prevent drying of the lake.
• Selective cutting of vegetation to provide defined pathways for water and oil to flow.

9.1.8 Case studies: freshwater spills - Lemon Creek, BC (2013)

Incident summary

• On July 26, 2013, a tanker truck carrying Jet A-1 fuel rolled into Lemon Creek, a fast-flowing tributary of the Slocan and Kootenay River System in the Kootenay Region of south-eastern BC, Canada.
• The incident site on Lemon Creek was approximately 4 km upstream of the confluence with the Slocan River.
• The Lemon Creek Forest Service Road was closed, and residents evacuated. A “Do Not Use” water order was issued for Lemon Creek, Slocan River and Kootenay River downstream to the Columbia River confluence.
• A recreational and water use ban was also implemented for the same restricted area.
• Approximately 32,850 L of Jet A-1 fuel was released into Lemon Creek:
  • 2,000 L of mixed water and product was recovered from the incident site by vacuum truck;
  • 1,600 tonnes of soil were removed during remedial excavation;
  • 20,000 kg of contaminated absorbent material and vegetation was contained and removed from the area.

Challenges identified

• Jet A-1 fuels are generally highly volatile, relatively insoluble and less dense than water; following the spill most of the components dispersed downstream on the surface of the water, however some components accumulated in slower moving reaches often associated with wood and log materials or held in coarser sediments.
• Moving water hindered booming and recovery efforts of the product.
• Flushing techniques were used to release product from stream banks and vegetation, accessible product was recovered using a vacuum truck.
• Sensitivity mapping had not previously been completed for this waterbody; as sensitivities were not documented, setting priorities for assessments and treatment was initially challenging.
• Watercraft restrictions required that most shoreline assessment efforts be carried out via downstream rafting.
• Assessment of the residual Jet A-1 product in the environment by SCAT required a new oiling matrix classification to provide traditional reporting of Heavy, Moderate, Light, Very light and Trace oiling.

Lessons learned and best management practices

• An Incident Command Post (ICP) implementing a basic Incident Command System (ICS) was quickly established by the responsible party (RP), agencies, and response organizations (RO’s) with the development of an Incident Action Plan (IAP) to instigate the emergency and remediation phase of the response.
• Activities to assess and manage source stabilization, salvage, containment and recovery, resources at risk, shoreline protection and recovery, wildlife protection and rehabilitation, human health and safety, and community concerns were undertaken, including sediment and water sampling programs.
• Aerial, boat and ground surveys were conducted to assess the scope of the affected area and to prioritize and direct treatment activities.
• The establishment of treatment criteria necessitated a unique set of guidelines to evaluate residual oil product in the environment. SCAT assessments for operational treatment criteria were developed based primarily on visible sheen and odour characteristics, while longer-term ecosystem recovery and human health treatment criteria were based on monitoring and sampling programs.
• The Slocan and Kootenay River System is a high-use recreational area and the restricted access during the summer months required an expedited, however thorough, assessment and treatment program.
• On August 6, 2013 the “Do Not Use” water restriction on the Kootenay River was lifted, on August 9, 2013 all remaining water restrictions were lifted except for lower Lemon Creek with ongoing monitoring.

9.1.9 Case studies: freshwater spills - Gogama, ON (2015)

Incident summary

• A derailment of 37 train cars occurred on March 7, 2015 located approximately 3 km northwest of the community of Gogama, ON, Canada.
• The product that was spilled was synthetic crude oil derived from heavy oil sources in western Canada.
  • Approximately 2.63 million L of crude oil were released to the environment (air, water, and ground).
• Crude oil was released directly into the Makami River and onto the ground north of the river.
• Effects were initially observed up to approximately 90 m upstream of the rail bridge and along the river from the rail bridge downstream to Lake Minisinakwa.
• In addition to the containment, collection, and remedial activities completed at the site, monitoring and sampling were completed along the river and in the lake.

Challenges identified

• Working on ice and in extreme cold weather (heavy snow and freezing rain).
• Oil present on and under ice as well as oil contaminated water between layers of ice at times.
• Oil emulsification.
• Small community with very limited logistics support and infrastructure – nearest populated towns are Timmins 114 km to the north and Sudbury 191 km to the south.
• Sensitive area with respect to biodiversity: fish spawning areas – silt sensitive; adjacent wetlands; significant use by migratory wildlife in spring.
• Fluctuating water level and river flow – hydroelectric generating station (dam) on river.

Lessons learned and best management practices

• Extensive ice slotting used to facilitate boom deployments to contain product close to source.
• Submerged wire baskets filled with oil snare, observation at ice profiling holes and under-ice video used to detect presence of submerged or subsurface oil during response.
• Extensive use of bubbling systems using compressed air and perforated weighted hose to:
  • maintain open-water;
  • create open-water between two ice slots;
  • melt ice containing oil;
  • aid in oil recovery.
• Water injection used to flush oil trapped in the water layer between layers of ice.
• Retaining ice along river banks during oil recovery prevented shoreline oiling.
• Pieces of ice covered with oil washed off in recovery area and treated ice placed in segregated area to melt.
• Pieces of ice with encapsulated oil removed and melted in frac tanks to recover oil.
• Oil was collected from the river and placed in temporary storage tanks – oil and oily water were transported off-site for disposal at various treatment facilities.
• Numerous SCAT assessments were completed on the Makami River and in Lake Minisinakwa from 2015 to 2017.

9.1.10 Case studies: freshwater spills - Pipeline Spill, North Saskatchewan River, SK (2016)

Incident summary

• On July 21, 2016, an estimated 225 m³ (1,415 bbls) of blended heavy oil and condensate was released from a 16-inch (40 cm) pipeline, 33 km northeast of Lloydminster, SK, Canada.
• The break occurred on land along the south side of the North Saskatchewan River, approximately 160 m from the river bank. Post release geotechnical engineering reports cited ground movement, caused by rain, as the cause of the pipeline failure.
• An estimated 60% of the released product was contained on land and the remaining 40% migrated to the river.
• Surveys following the release indicated that initial shoreline oiling was limited from the point of entry (POE) downstream 190 km; however a high-water flood event in late August 2016 redistributed oiled material, which had not been removed, further downstream with oiled woody material observed on shorelines as far as 486 km from the POE.
• SCAT surveyed over 960 km of river bank within 1,025 segments.
• Over 2,600 people supported the emergency response, including over 400 members from various Indigenous communities.

Challenges identified

• Fresh water intakes from the North Saskatchewan River for North Battleford, Melfort and Prince Albert were closed downstream of the POE, necessitating expeditious assessments and operations activities.
• Large project area (500 km of river) requiring access to both banks and multiple mid-channel islands. Most of the river access for survey and operations teams was via boat with only a few usable launch points.
• Limited access points increased transit times by road and boat, and shallow water and changing water levels made boat transit challenging.
• The length of the affected area, on the order of 2,000+ km of total river bank shorelines, meant that decisions on geographic priorities and on the level of detail for documentation were necessary – i.e. in 2017, a complete survey of the entire shorelines was impractical between ice breakup and the spring freshet.
• During the 2016 and 2017 field seasons, the changes in water levels associated with the spring freshets and unexpected summer flood conditions greatly influenced the oil distribution patterns and oil character producing four distinct data sets, making comparison over time difficult and necessitated innovative approaches to data processing and presentation.
• Turbulent flow during high water events also redistributed sediments within the river resulting in buried oil layers with varying degrees of unoiled overburden complicating the delineation of oiling and treatment operations.
• The abundance of beaver lodges along the river banks hindered both survey and operations activities – very large woody material piles were difficult for field teams to survey and treat.

Lessons learned and best management practices

• A Unified Command (UC) centre was setup at in Lloydminster implementing an Incident Command system (ICS) protocol for the response. The emergency response was large, dynamic, and multi-disciplinary in nature, including contributions from the responsible party (RP) staff, Indigenous communities, government personnel representing various provincial and federal agencies, and many technical professionals from independent consulting firms.
• A Technical Working Group, consisting of representatives from regulatory agencies, the RP, and third-party technical experts, was established to provide technical and scientific guidance for the response efforts.
• As the response evolved, long-term water and shoreline evaluation programs were undertaken, with survey and sampling programs in 2016, 2017, 2018, and 2019 to support treatment and remedial actions as well as monitoring both ecological and human health concerns along the river.
• The North Saskatchewan River had no existing detailed character mapping information requiring the development of a segmentation system to provide an effective documentation framework for river bank assessments and operational logistics planning. The system developed used mid-channel kilometre point (KP) markers (1 km apart) along the river with right bank, left bank and mid-channel (island) designations for individual shoreline segments between KP markers.
• Documentation and reporting procedures after the 2016 emergency phase were re-aligned (2017-2019) to follow the statutes as defined in the Saskatchewan Environmental Code, using a Corrective Action Plan (CAP) and Resource Based Objective (RBO) protocol in place of the standard Shoreline Treatment Recommendations (STR) and treatment criteria.
• Another feature of the multi-year program was the importance of recognizing that field data collection techniques must be flexible. SCAT documentation and survey procedures evolved (Forms, Apps and Database) to better meet the changing response requirements and reporting expectations.
• The need for calibration in space and time between SCAT teams and operations personnel was critical to provide consistent documentation and effective treatment options, particularly when the different water level events significantly altered the oiling character and shoreline conditions.
• A Complete-as-You-Go (CAYG) protocol was established with operations personnel embedded within the SCAT teams to treat light oiling found on shorelines. This approach was a significant time saver as three separate missions could be combined into one survey; initial oiling assessments, operations treatment and post treatment inspections (SCA-CAYG-SIR).
• The application of oil detection canines (ODCs) for surface detection in areas with light oiling conditions or with access constraints and for subsurface oil detection greatly increased the efficiency and accuracy of field assessment evaluations – also aided in relationship building with affected Indigenous communities.
• The use of SCAT assistants was introduced in order to ensure a consistent and calibrated field team as support from other response representatives was not always available.

9.1.11 Case studies: freshwater spills - South Salmo River, BC (2019)

Incident summary

• The incident occurred on March 27, 2019, 10 km south of Salmo, BC, when a double tanker truck went off the road near the Highway 3 and 6 junction spilling approx. 50,000 L of gasoline and diesel directly into the South Salmo River.
• A Unified Command (UC) was established and directed a SCAT survey program to locate and delineate the fuel below the point of entry (POE). Most of the product observed was in the South Salmo River from the POE to the confluence with the Salmo River 2 km downstream (Division A) and a small section of the Salmo River below the confluence (Division B).
• Water level forecasts indicated that the spring freshet would not be expected for some weeks and the UC determined that allowing natural attenuation was not acceptable and that a treatment action would be required.
• A Menzi Muck walking excavator (“spider excavator”) equipped with an articulating “grabber” attachment agitated the coarse river bed sediments (primarily cobble and boulders) to release the entrapped product.

Challenges identified

• The South Salmo and Salmo rivers are high-flow, relatively shallow rivers with limited backshore access beyond the POE.
• Access along steep river banks was possible using the walking excavator.
• SCAT support for the operations below the POE, where foot access was challenging, included real-time video feeds from a small Unmanned Aerial System (sUAS).
• Channel margins further downstream in the Salmo River (Divisions B and C) with mixed sediment substrate and natural collection areas (e.g. eddies, mid-channel bars, outside channels) were specifically targeted for oiling condition “spot checks” by a River Raft SCAT Team using a certified river raft guide and accompanied by a swift water rescue specialist.

Lessons learned and best management practices

• Although a relatively small release that affected a limited section of river, the SCAT program followed standard protocols with three (3) Shoreline Treatment Recommendations (STRs) generated to direct the operations and Segment Inspection Reports (SIRs) to document closure when the treatment criteria were achieved.
• One STR was generated for the POE area, the second for the shallow river downstream in Division A, and the third for the few oiled areas in Division B that required action; the latter two STRs were for locations with a relatively similar and uniform river bank character.
• Fifteen (15) SIR recommendations were completed and submitted to the UC for individual segments identified for treatment in Divisions A and B, and for the remaining untreated downstream areas.
• Safety was addressed by: (1) personnel with swift water rescue training and river rescue response equipment maintained during the entire response; (2) swift water rescue personnel positioned with walking excavator operations, SCAT shoreline surveys, and downstream raft surveys; (3) air monitoring maintained throughout the response during all operations (along shorelines and with the operator of the excavator while working in the river).

9.2 International freshwater oil spill response

9.2.1 Case studies: freshwater spills - Kolva River, Komi Republic, Russia (1994-95)

Incident summary

• A series of large crude oil spills at multiple locations occurred during the summer and fall of 1994 in a 70 km section of pipeline in the Komi Republic of Russia.
• The total volume of crude oil that was spilled in the project area was estimated to be over 1 million bbls.
• The spills created the threat that, in the spring of 1995, a large volume of this oil could be transported by a series of tributaries to the nearby Kolva River and then into the Pechora River – both rivers have large subsistence populations and there is a sensitive delta at the Arctic Ocean coast.

Challenges identified

• Multiple heavily oiled habitats: dry scrub and upland forest; lowland seasonally-submerged forest; raised and floating bogs; streams.
• Remote location with a few forest tracks and roads; Right Of Way access required amphibious, tracked vehicles; nearest town (Usinsk) 50 km distant by poor road; Usinsk only accessible by rail or air.
• Six individual major work areas with multiple spill locations along a 30 km length of the pipeline, each with unique challenges from small creeks to rivers and bogs.
• The strategy for containment was developed that involved the construction of temporary containment dams on the streams that drained the affected areas. The largest dam was a 1000 m long semi-circle, 5 m in height, with multiple siphon pipes to allow river through flow. The floating and raised bogs were divided into cells on the order of 750 m wide to allow access and oil recovery.
• The only construction materials available were glacial outwash silts, which were excavated from nearby borrow pits.

Lessons learned and best management practices

• Strategic choices in winter/spring 1995 before the spring high discharge that involved habitat modification with aggressive treatment to prevent oil reaching the Kolva and Pechora rivers.
• Multiple innovative techniques were required including the use of sections of pipe that were pulled across the floating bog within work cells to squeeze oil from the surface vegetation; new plant growth was observed within only a few weeks in the bog cells.
• SCAT survey methodologies developed for marine coastal environments and modified for the small streams of the spill region proved to be highly effective for describing and documenting the pre- and post-treatment oil conditions in the riverine environments.

9.2.2 Case studies: freshwater spills - Rio desaguadero Pipeline Spill, Bolivia (2000)

Incident summary

• On January 30, 2000 an estimated 29,000 bbls (4,610,600 L) of mixed crude oil and condensate was spilled from a pipeline, which was damaged during summer flood conditions, at the Desaguadero River crossing on the Bolivian Altiplano (approx. altitude of 3,700 m).
• The timing of the spill coincided with bankfull, flood conditions during the period of the highest rainy-season water levels – the oil was subjected to high energy and extremely turbulent flow conditions.
• The oil was transported as far as 350 km downstream and deposited along a total of approximately 400 km of river bank channels, meander floodplains, and irrigation ditches, as well as on several hundred hectares of low-lying floodplain.
• The downstream reaches of the river system are an extremely important habitat for aquatic birds; fortunately, the environmental effects were minimal and the ecologically important lakes (Uru Uru and Poop\xf3) were spared the effects of the spill as an extensive delta wetland system acted as a filter to trap the southerly moving oil.
• A second high-water level associated with high run-off in early March 2000 caused some of the stranded oil to be buried by an unoiled layer of silt.
• A treatment program using local labour was organized that peaked at a total of 3,200 in March and most of the oil removal was completed by the end of April 2000. A second phase program to remove oiled vegetation was carried out through the winter months to address perceived effects on forage and grazing animals.

Challenges identified

• Treatment operations were constrained by few crossing points over the river (bridges or hand-drawn ferries) and by the problems of access in the wetlands of the floodplain zone during the summer season.
• Oil was often stranded on the overbank regions of the river margins and across low flood plains making finding residual oil deposits difficult – most of the shoreline oiling was identified via aerial surveys.
• High altitude provided physical challenges for the non-Bolivian response team members.
• Helicopter and fixed-wing operations were limited due to drastically reduced payloads, and either fuel caches or fuel trucks were needed to support the survey activities.
• A rural population of about 30,000 that was dependent on family-based subsistence agriculture and animal husbandry (mainly cows and sheep, with some llama and pigs) – the river is the water supply for domestic use, cattle and irrigation.

Lessons learned and best management practices

• Aerial (helicopter) reconnaissance with video surveys covered more than 6,000 km of river to locate the oil and provide direction and priorities for the treatment program; pre-GPS systematic grid survey pattern used for the video survey of the delta areas.
• Access to the wetlands was difficult during the winter season and a decision was made to delay treatment of these areas until they dried out to avoid damage to the soil and vegetation.
• Treatment Criteria:
  • no 100% oil cover patches >3 mm thick and >50 by 50 cm (approximately the size of a shovel)
  • no single patches of >20% surface oil cover >10 m long, >1 m wide, and >3 mm thick
  • no liquid oil patches >1 m diameter that could be potentially remobilized
• Vegetation Removal Criteria:
  • more than 30% of stems with weathered oil or stain
  • more than 10% of stems with unweathered (fresh or sticky) oil)
• A 7-step procedure was developed in March for the approval of treatment activities on an area-by-area basis. The government chose not to participate in the process so that the “sign-off” process became an internal activity of the response team. Considerable emphasis was placed on the systematic and complete documentation of all residues that remained after the treatment criteria had been met.
• Sample analyses demonstrated a significant amount of Oil-Mineral Aggregate (OMA) formation in the low salinity waters. This promoted dispersion of the oil in the flood plains and enhanced natural biodegradation rates.
• The overall environmental risk was reduced due to the extensive and rapid weathering of the spilled oil. The water-soluble fractions were lost rapidly, within a few weeks if not days, in the weathering process. As much as 70% of the total hydrocarbons and 90% of the total PAH were lost so that the residual oil was primarily heavy hydrocarbons that were immobile and not readily bio-available.
• An extensive veterinarian program examined more than 400,000 animals to provide inoculations in areas of oiled forage.

9.2.3 Case studies: freshwater spills - Pipeline Spill, Yellowstone River, uSA (2011)

Incident summary

• On July 1, 2011 a 30 cm (12 inch) crude oil pipeline breached in the vicinity of or under the Yellowstone River near Laurel, MT releasing an estimated 750 to 1,000 bbls (119,240 to 158,987 L) of crude oil into the river.
• The 22.5 km (14 mile) section of pipeline between adjacent pump stations, which crossed beneath the flooded Yellowstone River where the breach is suspected to have occurred, likely filled with river water, displacing a significant amount of oil that floated to the surface.
• The oil was observed in Billings, MT approximately 24 km (15 miles) east early in the morning (02:00) of July 2, 2011 and by 09:00 approximately 64 km (40 miles) downriver (east) from the spill site.
• The oil was widely dispersed along the banks and adjacent overbank lowland areas due to the flood stage conditions of the river at the time of the release.
• Assessments of the river indicate that the high flow conditions had washed away a significant fraction of the oil, with only limited amounts pooled in the floodplain or riparian wetland areas and substantial amounts of soiled vegetation and upland (overbank) tracts along the river.
• Shoreline oiling was confirmed as far as 116 km (72 miles) downstream from the spill site.

Challenges identified

• The river was in flood stage at the time of the release, which posed significant safety risks for responders and hindered efforts at containment booming and recovery on the main river channels.
• Conditions on the river including high velocity flow, flood stage water levels, and large material (trees and logs) floating in the current dictated that conservative measures be used until the water level receded – limited use of smaller boats near shorelines, in backwaters and side channels were used to recover oil and employ sorbent materials
• Due to high water levels initial SCAT team reconnaissance observations were performed by air or boat; later SCAT surveys and oiling documentation were performed on foot along shorelines and potential overbank areas.
• The process of initiating remediation activities required gaining permission to access river shorelines from property owners and trusties, including private parties, Bureau of Land Management (BLM), State of Montana and various county authorities.
• Culturally sensitive areas identified by the Local Apsáaloke Tribe required both archaeological and tribe personnel during assessments and subsequent treatment activities.
• Where land access was not granted by the landowner, SCAT surveys were limited to on-boat shoreline observations only, with no overbank documentation for treatment or damage assessments.

Lessons learned and best management practices

• A Unified Command (UC) was established by the US Environmental Protection Agency (USEPA) and the responsible party (RP) with State and local agency participation
• An Incident Action Plan (IAP) was developed to manage the response activates as specified under Incident Command System (ICS) procedures.
• In addition, the USEPA issued an administrative order requiring certain activities to remediate the release pursuant to the Clean Water Act.
• A SCAT Plan was developed, and SCAT teams were established ensuring a multi-agency consensus approach with potential participation from the USEPA, Montana Department of Environmental Quality (MDEQ), United States Coast Guard (USCG), City of Laurel Public Works, Apsáalooke Tribe, Montana Department of Natural Resources and Conservation (DNRC), Bureau of Land Management (BLM), and the RP and their contractors.
• The RP mobilized hundreds of response contractors to the affected areas between Laurel and Billings, while maintaining a reserve strike force to address any pockets of oil that were found anywhere along the river by aerial reconnaissance, ground surveillance, and reports from the public and local officials.
• During the response, International Bird Rescue (IBR), US Fish and Wildlife Service, and Montana – Fish, Wildlife and Parks identified locations where oiling presented a greater than normal hazard to wildlife.
• As specified in the Wildlife Plan implemented for the response, inspections continued in many segments following closure of the segment by the SCAT process in order to ensure that all wildlife hazards had been identified and abated.

9.3 Key lessons learned from case studies

Based on a review of the freshwater oil spill responses presented in the previous sections, the following Table 9.1 provides an overview of key lessons learned, some specific to select habitats or freshwater environments and others more general in nature, that are important to consider in preparation for the next incident to affect a freshwater waterway. Specific lessons learned or best management practices for treatment techniques are reflected in Shoreline Treatment Information Sheets (Section 6.4.1).

Table 9.1 Freshwater spills – key lessons learned from case studies