An emerging concern for construction workers in sewer lines and wastewater treatment plants

MOST SEWAGE COLLECTION and treatment systems in the U.S. are 30 to 100 years old [EPA(b)] with a total estimated value exceeding $1 trillion [EPA(a)]. EPA estimates that in the year 2000, more than 1.2 billion gallons of raw sewage poured into waterways due to overflow, blockage, leakage or other system faults [EPA(b)]. The construction projects needed to correct these problems will be many and enormous. Upgrades to the City of Atlanta sewage system alone are estimated to cost around $3 billion (Copeland A3). The problem is not limited to large metropolitan areas. A study by the Minnesota Pollution Control Agency suggests that $1.2 billion must be invested in wastewater facilities in rural Minnesota over the next 20 years (Franklin B3). As the nation’s urban infrastructure continues to expand, age and deteriorate, and as the public’s concern for environmental quality increases, construction work in active sewer lines and wastewater treatment plants (WWTPs) will grow. As a result, more construction contractors and workers will be exposed to the hazards associated with working in these locations. Most construction contractors are aware of the obvious health hazards of working in sewers or WWTP. For many, it is standard procedure to monitor sewers and WWTPs for combustible gas, oxygen deficiency and hydrogen sulfide, and to take appropriate precautions to minimize these hazards. However, because of the publicity surrounding diseases such as AIDS and the hepatitis B virus (HBV), as well as regulations such as OSHA’s Bloodborne Pathogens Standard, new concerns and questions are being raised about the biohazards that may be present in these environments. Construction safety professionals must also be aware of the potential for exposure to chemicals used in WWTPs (e.g., chlorine, ozone) or those that may contaminate raw sewage (e.g., solvents, heavy metals). In some cases, these may pose a greater risk to workers than the biohazards.