7. HEALTH AND SAFETY
Stormwater monitoring involves activities that have the potential to adversely affect the health and safety of field personnel. Stormwater monitoring field crews often work in wet, cold, and poor visibility conditions. Sampling sites may be located in highways, stream channels, or remote, poorly lit areas that need to be accessed on a 24-hour basis. Monitoring personnel and workers installing or maintaining equipment may be exposed to traffic hazards, confined spaces, biological hazards (e.g., medical waste and fecal matter), vectors (e.g., snakes and rats), fall hazards, hazardous materials, fast moving stormwater, and slippery conditions. The information contained herein is for guidance only, and does not supersede or otherwise change any applicable state, local, or agency health and safety requirements or programs. A health and safety plan should be developed for each site.
The following sections describe health and safety requirements for stormwater monitoring programs and are useful for evaluating the implications of these requirements during equipment selection and monitoring plan development. An example health and safety plan is provided in Appendix B.
7.1. Health and Safety During Field Activities
Health and safety of field crews during installation, maintenance, and monitoring activities should be of primary importance when selecting a monitoring site and associated monitoring equipment. This section describes some of the potentially hazardous activities typically conducted as part of monitoring program implementation.
Equipment installation and routine maintenance
Flow meters, water samplers, and ancillary equipment may need to be installed, depending on the objectives and scope of the monitoring program. Installation usually requires entry into confined spaces and the use of power tools. As required by OSHA, all personnel entering confined spaces must be properly trained and certified for confined space entry. The flow meter and automatic water sampler are often suspended within the manhole chamber or are located in an equipment shelter. Sampler intakes and flow meter sensors are secured to the stormwater conduit using mounting straps. Sample tubing and sensor cables are secured and routed to the water sampler and flow meter. Routine maintenance consists of visual inspections of sampler intakes, flow meter sensors, mounting hardware, and equipment desiccants (moisture adsorbent). Equipment calibrations may also be performed during maintenance visits.
Establish work zone and traffic controls
Field crews may need to establish safe work zones and, in some cases, provide traffic control. All work zones and traffic control systems must provide for the safety of both field crews and the general public (and must comply with applicable regulations regarding traffic control).
Opening and closing manholes
Field crews may need to remove and replace manhole covers. Manhole lids should be removed and replaced using a specially designed manhole hook.
Flow meter and automatic water sampler setup
Both the flow meter and automatic water sampler will need to be programmed and started before each storm. The sampler is made operational by a keypad located on the sampler. The flow meter is made operational by using a keypad, laptop computer, or telemetry. If the keypad is used, confined space entry may be required since the meter is often located in the manhole chamber.
Remove and replace automatic water sampler
Automatic water samplers sited in manhole chambers will need to be removed and replaced to service the sample bottles (i.e., install, check, remove). A cable harness can be rigged as the lifting handle. Full samplers can weigh between 60 and 70 pounds, so lifting is an issue. Often hoists must be employed.
Collect grab samples
Collecting grab samples requires using a manual sampling device such as a stainless steel or plastic beaker attached to a lanyard, pole, or other dipping apparatus. The sampler is lowered into the flow stream to collect the sample, which is then transferred into sample bottles.
7.2. Potential Hazards During Sampling
This section further describes potential hazards to field personnel that may be encountered during monitoring activities. These hazards are presented to provide a context for the equipment selection process. Many monitoring approaches help to minimize exposure of personnel and the public to potential hazards. The summary provided here is not intended to include every type of hazard that could be encountered; rather, it is intended to serve as a starting point for a site-specific analysis for a given project.
Storm sewers are classified as "confined spaces" under OSHA regulations. Regulations for entry into confined spaces are contained in Federal Register 29 CFR 1910.146 and in possibly more stringent state regulations. The regulations require that no person shall enter a confined space without proper training and equipment. The risks associated with confined spaces include dangerous atmospheres, engulfment, falls, falling objects, and bodily harm due to explosion and biological hazards.
Traffic hazards will be encountered when working on the side of or on a highway. These hazards are greatest during times of reduced visibility, such as during storm events and at night. The primary threats associated with working in or alongside roadways are workers being struck by passing vehicles or being involved in a vehicular collision. The risk associated with these threats is severe bodily injury or death.
Open Manholes and Manhole Lids
Storm sewer sampling sites are often located below grade, such that manholes must be opened during water sample collection and equipment maintenance activities. Opening manholes requires the removal of heavy steel lids. Improper manhole lid removal techniques can result in back injuries and/or crushed toes or feet. Specially designed manhole hooks along with proper lifting techniques provide the easiest and safest way for removing manhole lids.
Open manholes pose a threat to workers and the general public. Limited visibility, inattention, poor site control, slips, and/or trips could result in someone falling into an open manhole. The risks of such a fall include minor to fatal bodily injury.
Open Water Hazards
High flows commonly associated with storm events present a threat to workers. Slippery conditions, stream-side vegetation, and unstable stream banks could cause a worker to fall into a stream. The risks of such a fall include hypothermia, bodily injury, and drowning.
Rodents, pathogenic microorganisms, snakes, and viruses are potential biological hazards of concern. The primary threats associated with these hazards are bites and/or the contraction of diseases or infections.
Although most stormwater sewers are not intended to contain hazardous materials, there is a potential for hazardous gaseous and/or liquid contaminants to be present as the result of industrial runoff, illicit storm sewer connections, and/or illegal dumping of waste. The presence of chemicals and/or chemical vapors may result in (but are not limited to) one or more of the following threats: toxic conditions, oxygen displacement, explosion, and/or fire. The risks associated with these threats include poisoning (acute and/or chronic), asphyxiation, and bodily injury.
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