CSA Z275.2-15 Occupational Safety Code for Diving Operations

Interpretation #1 Diving in Contaminated Environments

1. Question: Is it the intention of CSA Z275.2 that be an available option for diving in contaminated environments under controlled conditions (as per Clause 11 and Table 8)? Answer: Yes

2. Question: Is it the intention of CSA Z275.2 that SCUBA diving be an available option with no differentiation between occupational diving user groups (e.g. it is not for police or scientific divers only)? Answer: Yes

Explanation:

Clause 7.1.4 SCUBA shall not be used for diving operations that involve a) welding; b) burning/cutting; c) high- jetting; d) hoisting; e) dredging; f) the use of power tools; or g) the use or handling of explosives [with the exception of the clearance/remediation of unexploded explosive ordnance (UXO), provided that a assessment has determined that the use of surface supply diving techniques and equipment would lead to an increased risk and specific tasks associated with or improvised explosive devices (IEDs)]. For UXO and police diving operations, see CSA Z275.6.

Commentary: The intent of Clause 7.1.4 is to exclude the use of SCUBA from specific work environments and processes and, although it no longer specifically excludes the use of SCUBA in contaminated environments, there are still restrictions in place. Conditions for the use of SCUBA for diving in contaminated environments are detailed in Clause 11 and Table 8. The use of SCUBA for this type of diving is limited to conditions where a , including adequate water sampling, indicates that the level of contamination is clearly within Categories 3 or 4, see Clause 11 and Table 8.

------Clause 11.3.3 Where identification of contaminants is not determined prior to any diving operation that needs to be performed, the minimum standards of protection for all personnel (as detailed in Table 8) shall be as detailed for Category 2 (CAT 2).

Commentary: The intent of Clause 11.3.3 is to provide a baseline or “default” condition for diving in contaminated environments. If there is any doubt as to the nature of the contamination, then the water is to be treated as per Category (CAT) 2 at a minimum. CAT 2 requires the use of a surface-supplied diving system with full encapsulation of in a , see Table 8.

------Clause 11.3.4 The following additional criteria shall be used during the planning of a diving operation: a) level of personnel training and proficiency b) equipment selection and compatibility with identified contaminant(s); Note: If diving in hydrocarbons, natural rubber or latex is preferred over silicone. c) protection measures to minimize the exposure of divers and surface support personnel; d) decontamination of divers, surface support personnel, and equipment; e) requirements (see Clause 11.10); and f) specific diving scenarios that increase the potential exposure to contamination, such as run-off after heavy rainfall, working in sediment, working adjacent to points of discharge, and human remains recovery.

Commentary:  Clause 11.3.4 highlights the importance of completing a thorough risk assessment, including job (JHA), using all available information on the potential exposure of the dive team to contaminants (see Clause 11.3.2 for specific requirements). The risk assessment should be based on the particular location and situation of the intended diving area.  Personnel training and competency are key aspects in this process. Training in contaminated water diving to the competency levels required by CSA 275.4 for Unrestricted Surface Supply Diver, or equivalent training that is acceptable to the authority having jurisdiction, is recommended.  Equipment selection should take into account the limitations of various diving techniques, especially if the use of SCUBA is under consideration (CAT 3 and CAT 4 only). Surface-supplied generally provides a higher level of safety when diving in contaminated environments but it is recognized that this technique may not be appropriate in all scenarios.  If any of the specific diving scenarios identified above are present, it is recommended that additional measures, over and above the minimum standards of protection in Table 8, are implemented.

------Clause 11.6 Contaminated water diving categories Hazard categories for contaminated water diving are detailed in Table 8. Note: The categories used in this Standard follow established U.S. Navy guidance and practices.

Commentary: It is recommended that authorities having jurisdiction for ports, harbours, and other defined areas of underwater activity designate dive sites using these categories. It is also recommended that, when contaminated water assessments are performed (see Clause 11.3.2), the approaches recommended by Health Canada Guidelines for Canadian Recreational Water Quality are used to assist with such categorization.

------Clause 11.8 Minimum crew In addition to the minimum crew standards required by Clause 7 (SCUBA diving) and Clause 8 (surface-supplied diving), at least one extra crew member/tender shall be present at all times.

Commentary:  The intent of Clause 11.8 is to highlight the need for extra personnel when diving in a contaminated environment.  The requirement for an extra crew member/tender addresses additional demands placed on support personnel working in a contaminated environment such as implementing access control measures, and assisting with decontamination.  The crew size for SCUBA must also respect the existing minimum crew size requirements of Clause 7.5.  The crew size for surface-supplied diving must also respect the existing minimum crew size requirements of Clauses 8.2.1.1 and 8.2.1.2.

------Table 8 Contaminated water diving (CWD) — Categories and minimum standards of protection

CAT 1 Grossly contaminated water Explanatory information CAT 1 diving presents an extreme level of risk for which specialized equipment and procedures are required. Other techniques should always be considered before diving in a CAT 1 environment.

EXAMPLE: Diving in locations where potential for radioactive or lethal contamination exists.

Commentary: Diving is not recommended in CAT 1 environments due to the extreme risk involved. Other techniques, such as the use of a Remotely Operated Vehicle (ROV), are strongly recommended instead of diving wherever possible. Diving in CAT 1 environments should only be considered in an emergency and under the oversight of the authority having jurisdiction.

CAT 2 Heavily contaminated water Explanatory information CAT 2 diving is commonly encountered during occupational diving in industrial environments or following incidents involving chemicals or oils.

EXAMPLE: Diving in sewage, industrial clarification plants, tanks or contained bodies of water with high of oil- based contaminants or corrosive materials, visible fuel slicks, aircraft recovery operations with copious jet fuel present.

Commentary: CAT 2 is the baseline or “default” condition for diving in contaminated environments and the minimum standards of protection for CAT 2 should be applied if there is doubt as to the nature of the contamination. Examples of CAT 2 scenarios include diving in major commercial ports (where there is no risk assessment or designation of the dive site), including ports managed by port authorities created under the Canada Marine Act, and any port area where commercial vessels are undergoing fuelling, loading, or cleaning (this includes tank flushing or discharge overboard). Major commercial ports in Canada include St John’s NL, Halifax NS, Montreal QC, Toronto ON, and Vancouver BC.

CAT 3 Moderately contaminated water (MCW) Explanatory information CAT 3 diving covers routine diving activity where there is some, mainly biological, risk and precautions shall be taken to avoid water ingestion and entry through skin cuts, abrasions, or unhealed wounds.

EXAMPLE: Harbours, locations adjacent to points of contaminant discharge, and other locations where concern exists for contaminants (e.g., sewage treatment outfalls), especially biological, that may easily enter the body through the mouth.

Commentary: The implementation of CAT 3 minimum standards of protection, instead of CAT 4, is recommended in the following circumstances: a) Whenever the guideline values for primary indicators of faecal contamination for primary contact activities, in freshwater and marine waters, as detailed in the latest edition of the Health Canada Guidelines for Canadian Recreational Water Quality, are reached or exceeded. b) Whenever the authority having jurisdiction issues a swimming advisory, or beach closure notice, identifying that the area is not suitable for recreational water use. This may be due to the presence of biological contamination (i.e. faecal - E. coli or Enterococci), toxins, or another water quality hazard. c) Whenever there is any potential risk from inhalation of aerosolized contaminated water. d) Whenever there is any potential risk of skin or mucous membrane contact with contaminants that are present in limited quantities and in low concentrations/diluted form. Examples of this type of diving task include motor vehicle recovery tasks (i.e. leaking gasoline and/or engine oil hazard), or inspection of vessel hulls coated with bottom (anti-fouling) paints that contain, or are suspected of containing, tributyltins (TBT).

CAT 3 SCUBA Minimum standards for diver’s dress and equipment a) full face mask (FFM) with integrated 2nd stage regulator (see Note 5); b) 2nd stage regulator to have separate inhalation and exhalation channels; c) dry suit (see Note 1); d) hood (see Note 6); e) gloves; and f) two-way voice communication system

Note: 5) A full face mask with natural rubber skirt is recommended when a high of oil or hydrocarbon contamination is expected (silicone components degrade faster in this situation). Note: 6) The full face mask shall overlay and seal onto the hood without leakage. A latex sealing surface on the hood is recommended. All-neoprene hoods are generally unsuitable for CWD due to poor face-sealing qualities.

Commentary:  The use of "standard" SCUBA (i.e. half mask and separate 2nd stage regulator with mouthpiece) is not permitted in CAT 3.  Only SCUBA with a full face mask (FFM), meeting the criteria detailed in Table 8, is permitted for diving in a CAT 3 environment.  The limitations of SCUBA diving techniques and equipment should be recognized and considered when conducting a JHA. SCUBA is a “tool in the tool box” and the use of SCUBA is permitted subject to adequate planning and risk assessment.  The use of a FFM that provides positive pressure inside the mask should be considered.  The provision of a bailout gas supply for each diver is required for all SCUBA diving, see Clause 4.6.2. When using SCUBA for diving in a CAT 3 environment the bailout configuration should include an easily accessible, diver-operated, block for switching to the bailout gas supply without the need to remove the FFM.  When using SCUBA for diving in a CAT 3 environment, the following minimum SCUBA configuration is recommended: a) full face mask (FFM) with integrated 2nd stage regulator (see Note 5); b) 2nd stage regulator to have separate inhalation and exhalation channels; exhalation channel to be a double exhaust design; c) diver-operated switch block for the bailout gas supply (without the need to remove the FFM); d) dry suit (see Note 1); e) hood - a dry suit with attached dry hood (see Note 6); f) gloves - waterproof (i.e. dry) gloves attached to suit with cuff rings or equivalent sealing system; and g) two-way voice communication system.

CSA STANDARD Z275.2-15

OCCUPATION SAFETY CODE FOR DIVING OPERATIONS

DRAFT INTERPRETATION – DIVING IN CONTAMINATED ENVIRONMENTS

NEW REFERENCE PUBLICATIONS

United States Navy, Naval Sea Systems Command - Guidance for Diving In Contaminated Waters SS521-AJ-PRO-010, Revision 1, 15 March 2008

Health Canada (2012). Guidelines for Canadian Recreational Water Quality, Third Edition. Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario. (Catalogue No H129-15/2012E).

Government of Canada - Canada Marine Act, S.C. 1998, c. 10