GUIDELINES FOR APPLYING HELCOM RECOMMENDATION 11/13 ON DEVELOPMENT OF NATIONAL ABILITY TO RESPOND TO SPILLAGES OF OIL AND OTHER HARMFUL SUBSTANCES

- approved by the Combatting Committee (CC 17) in 1993 and endorsed by the Helsinki Commission (HELCOM 15) in 1994

1. INTRODUCTION

The purpose of these guidelines is to specify detailed technical and operational demands concerning the implementation of HELCOM Recommendation 11/13 on development of national ability to respond to spillages of oil and other harmful substances.

It must be realized that due to adverse weather conditions and probable local limitations the demanded operational and technical means can not always ensure a successful cleaning operation at sea.

2. SPILL SPREADING

2.1 Oil

Oil spill spreading is a very fast process calling for immediate reactions with a maximum of recovery vessels in order to use effectively the first spreading phase with appropriate layer thicknesses. Experiences have shown that the key of effective recovery lies in the first 24 hours after a spontaneous outflow. The layer thickness in relation to the elapsed time and the potential surface sweeping performance must be used for the definition of the needed capacity, taking into account weathering of the oil, type and viscosity, sea state and wind influences.

2.2 Liquid substances

Spreading, dispersion and dissolution of liquid chemicals in almost all cases runs much faster; the tracing of this process is often very difficult as many of the floating substances are colourless and odourless with a very low viscosity.

Response measures in case of chemical spillages often have to be limited to tracing the remnants of the released substance and to alert threatened population or ship crews.

Aerial reconnaissance flights, especially with helicopters, are hereby a very helpful tool to position the combatting units in those areas where most of the outflow is concentrated.

3. DETECTION AND MONITORING

The detectability of a discharged hazardous liquid substance includes the localizing, identification and tracing of the substance in the aquatic environment. This precondition for adequate response measures depends mainly on the density, vapour pressure, solubility, viscosity, surface and interfacial tension, colour and odour of the substance. Most of these properties are relevant also for the penetration in the sea bottom sediment. For their own safety and for supporting salvage and recovery actions response units must have a minimum standard of detection tools (detection kits) to ensure a minimum of risk for involved crew members.

For situation and safety analysis in case of response spills, several measurements and observations are needed, such as:

- identification of the polluter
- identification of the pollutant
- measuring the properties of the pollutant
- localizing the polluted area
- determining the dimensions of the polluted area
- hazard identification
- measuring details regarding the atmospheric conditions prevailing on the spill site.

To protect response personnel and the area immediately affected, the chemical spill and its hazards should be assessed prior to undertaking counter-pollution actions.

4. SKIMMER PERFORMANCE

Based on a certain outflow quantity one might use the skimmer performances per hour in order to quantify the recovery capacity per day or within two days, but the manufacturers' figures are mostly based on extremely favourable circumstances with unrealistic layer thicknesses and assuming also a calm sea surface. Therefore, those figures are neither comparable nor reliable, as the Baltic Sea States operate various skimmer systems.

5. CONTAINMENT BOOMS

A provision of having a certain length of containment booms available could be an appropriate part of the specified equipment. The length of the boom capacity could be orientated on the fact that e.g. a spill caused by 10,000 m3 of oil will after 24 hours cover an area of 30-60 km2. But the main part of the total outflow is concentrated mostly on an area covering only 10 percent of the whole contaminated surface. Assuming that this slick concentration is drifting within the down-wind side of the moving slick then a total length of 2,000 m is needed to ensure that most of the slick concentration is surrounded.

But those countries which have based their recovery capacity on self-propelled skimmer ships with e.g. sweeping arms/spring-sweep systems or combination of deflecting containment booms with skimmer devices in the apex of the V-shape may prefer a higher sweeping capacity - see 6.2 - which can compensate large lengths of high sea booms in combination with various skimmer types.

Consequently, the following minimum requirements are demanded for:

- containment sea boom lengths, with auxiliary vessels to launch booms and deploy skimmers
- autonomous self driven skimmer ships with the definition of cleaning performance per day in km2
- performance per day of adhesion/suction devices like belt-disc skimmer/weir and vortex skimmers.

6. CAPACITIES TO RECOVER VARIOUS PERSISTENT OIL TYPES

The minimum requirements are as follows:

6.1 2,000 m high sea booms

6.2 2.5 km2 of sweeping performance. The calculated area is hereby based on a working speed of 1-2 knots of the sweeping or skimming vessels. A sweeping area of 4.5 km2 has to be fulfilled by those countries which mainly use autonomous drive skimmer ships. The total boom length of 2,000 m can be diminished to 1,200 m if the sweeping capacity is considerably greater.

6.3 Six (6) high performance sea skimmers with full sets of auxiliary equipment.

6.4 Sufficient storage tank capacity should be available at sea for continuous operations. The land-based disposal arrangements of the recovered mixture close to the potential sea areas must also be ensured.

7. REQUIREMENTS TO RECOVERY/RESPONSE VESSELS

7.1 Minimum required measuring equipment on board a response vessel:

a) Generally, response ships that could be involved in the release of hazardous materials should be permanently equipped with an adequate supply of protective clothing and breathing apparatus for those crew members likely to become involved in responding to an emergency spill situation. For the detection, the determination of the dimension or the determination of the concentration of a spill, several measuring devices will be needed.

It is recommended to have on board a response vessel the following safety and protection equipment:

- protective clothing (oilskins, gloves, full protective suit, breathing hood, goggles, respirators, canister-type mask, oxygen breathing apparatus, face mask or hood)
- devices for measuring toxic atmosphere (chemical reaction tubes)
- explosive meter
- photo or flame ionisation detector
- sampling devices
- flash point meter
- pH-meter
- electric conductivity meter
- radiation meter
- oxygen meter
- thermometer
- test kit.

b) In addition to this basic equipment it is advisable to be equipped with side scanning sonars and echo sounders with high sensitivity and high ground resolution. Bottom sampling devices and visual perception by remote controlled TV-cameras or TV-cameras operated by divers.

7.2 Each Contracting Party should have precautions made to provide, in case of emergency lightering operations, sufficient tank capacity to ensure the refloating of a grounded vessel or to lighter endangered tank capacity, e.g. by settling a model contract with tankship owners or tankship owners' association.

7.3 Salvage and recovery of sunken or lost packaged dangerous goods

The response unit should have or make arrangements for sufficient space on board to store recovered packages with leaking corrosive or toxic contents in a water-protected and air-tight space; alternatively special containers meeting the aforementioned properties can also be used for provisional storage of harmful packages.

A set of overpacks is needed to transfer leaking drums or cylinders with compressed or radioactive substances in emergency situations.

Each Contracting Party should ensure that in case of responding to a chemical spill including salvage or recovery of packaged goods the response unit and the strike teams on board must be equipped and/or protected to encounter the following hazards:

- combustibility
- corrosivity
- explosiveness
- flammability
- radioactivity
- toxicity in air and in water.