11/13/14

Ebola - Update for Wastewater & Biosolids Workers

Interim information on the potential risks from ebola virus, should further cases occur in the North America.

Many sectors in the U. S. and Canada have been improving protocols and preparations regarding the potential for an ebola outbreak.  There have been only a few cases of ebola documented in the U. S., and all but one have been successfully treated.  Currently, there is negligible risk in the U.S.  However, careful consideration is appropriate, given the severity of the illness caused by the ebola virus.  

The wastewater management profession has taken ebola seriously and is working with the Centers for Disease Control (CDC) and others to understand and address any risks to wastewater management professionals.  In early November, WEF conducted a webinar on the topic, which can be viewed via the WEF website.  Various organizations involved in wastewater treatment are expressing concerns about unknowns regarding such questions as how long ebola virus can remain viable in various environmental media and whether there may be some risk of it being transmitted to wastewater workers.  CDC officials do not think it likely and have stressed that even some people sharing living space with ebola victims do not become infected. Ebola is transmitted by close, direct contact with bodily fluids of an infected person who is displaying symptoms.

Sometime soon, CDC is supposed to release an interim guidance for protecting wastewater workers.  Already, some water resource recovery facility managers are recommending or requiring more thorough use of personal protective equipment (PPE), especially by those working on collection systems and pump stations, which are closer in space and time to potential discharges of ebola-containing wastes.  And some wastewater treatment facilities have worked proactively with local hospitals to ensure that any bodily fluids from known ebola patients will be disinfected prior to discharge to the sewer system.

And what about potential risks to those involved in biosolids management?  The research is not completely clear on this either.  However, it is very likely that risks to workers via biosolids โ€“ which have been further treated โ€“ are lower than those in collection systems and wastewater treatment processes.  According to CDC, ebola virus likely behaves similarly to other envelope viruses: they are some of the most susceptible to being killed in the wastewater and solids treatment processes, and they do not survive long in typical environmental conditions.  CDC considers the risk of transmission of similar envelope viruses via wastewater to be low.  Class A biosolids have gone through treatments that inactivate or remove such viruses and other pathogens, making them safe for public use.  Class B biosolids, on the other hand, may contain reduced levels of viable pathogens (but ebola is not likely to be one of those that survives).  There already exists NIOSH guidance to reduce risks to workers exposed to Class B biosolids.   It stresses common sense precautions such as avoiding inadvertent ingestion of biosolids (e.g. via eating or smoking during work), regular hand-washing, and use of PPE.

The latest information can be found at CDC (watch for the interim ebola guidance for wastewater professionals) and WEF.