Page 255 - Vessel Sanitation Program 2018 Operations Manual

VSP 2018 Operations Manual
13.9
13.9.1 Fecal and Vomit Accident Response for RWFs
Annex 13.9: Fecal, Vomit, and Blood Accident Response for RWFs; 202
Fecal, Vomit, and Blood Accident Response for RWFs
This annex includes a sample fecal accident plan and sample fecal accident log
required data elements. The sample fecal accident plan is based in part on
recommendations found on CDC’s Healthy Swimming website
(www.cdc.gov/healthywater/swimming).
In the sample plan (13.9.1.1), two tables address chlorine residuals and contact
times to be used for DISINFECTION after an accident involving fecal material
or vomitus. Each table has chlorine residuals and contact times that reduce the
risk for recreational water illness based on the pathogenic organisms that might
be present as a result of a fecal or vomit accident.
• The Residual and Contact Time for Loose Stool table shows chlorine
residuals and contact times to address loose stools. The primary
pathogenic organism of concern in loose stool is Cryptosporidum. This
organism is highly chlorine resistant; to destroy it, a CT VALUE of
15,300 is required. This means that when the chlorine residual in ppm is
multiplied by the contact time in minutes, a minimum of 15,300 is
required.
o Concentration (ppm) X Contact Time (minutes) ≥ 15,300
• The Residual and Contact Time for Formed Stool or Vomitus table
shows chlorine residuals and contact times to address accidents involving
formed stools or vomitus. The disease-causing organisms of primary
concern are Giardia, E. coli 0157:H7, and Shigella. To destroy the more
highly chlorine resistant of these organisms (Giardia), a CT VALUE of
45 is required. This means that when the chlorine residual in ppm is
multiplied by the contact time in minutes, a minimum of 45 is required.
o Concentration (ppm) X Contact Time (minutes) ≥ 45
To determine the appropriate chlorine residual and contact time, operators
should observe the nature of the accident.
• If the fecal accident is loose (diarrhea), the loose-stool table should be
used for DISINFECTION.
• If the fecal material is solid or formed or if the accident involves
vomitus, the formed stool or vomitus table should be used for
DISINFECTION.
It is important to remember that the DISINFECTION capabilities of chlorine
diminish as pH increases. Operators should ensure that pH levels are maintained
7.5 or less at 77°F (25°C) or higher during this DISINFECTION process.