Ashley Valley Water Treatment Plant - Executive Summary

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Ashley Valley Water Treatment Plant 
3550 North 2500 West 
Vernal, Utah 84078 
The Ashley Valley Water Treatment Plant (AVWTP), with an initial design capacity of 15 million 
gallons of finished potable water per day, was constructed by the Central Utah Water 
Conservancy District (CUWCD) in 1984/1985.  Since beginning production in December of 1985 the 
AVWTP has provided a high quality of safe drinking water to the customers of the Uintah Water 
Conservancy District (UWCD) which include Vernal City and other entities in the Uintah Basin.  
In it's continuing efforts to consistently maintain the high quality and safety of the water provided 
to the residents in our area served, the AVWTP uses Chlorine to disinfect the drinking water prior 
to delivery into the service area. Chlorine is the most widely used disinfectant. It has been safely used to disinfect drinking water for nearly 100 years, reducing or eliminating the risk of such water borne dise 
ases as cholera, typhoid and dysentery. THe chlorine we use is stored here at our facility.  The chlorine is delivered to the AVWTP in one ton containers and is injected into the water system direct from these containers.  The AVWTP personnel recognize the important protection that chlorine provides in our drinking water, but at the same time, we recognize the hazards that chlorine can present if not handled and used properly and safely. 
In order to be responsible to the residents in our area and protect them from possible harm in the 
event of an unexpected release of chlorine , the AVWTP, using United States Environmental 
Protection Agency (EPA) requirements and modeling guidelines, modeled two possible situations. 
The first situation, or worst case scenario, involved the most massive of all possibilities and the 
second scenario represented a more reasonable possibility of what might happen in an unexpected 
The first situation, or "worse case scenario", is based on the comp 
lete dumping of a full one ton 
container of liquid chlorine within a ten minute period of time.  This unlikely event, if it happened, 
could affect an area within 0.9 mile (4,752 feet) of the water plant.  This would most likely 
require the evacuation of about twenty residents in the area.  The second situation, a more 
reasonable scenario of what might happen, would be contained within a radius of less than 320 
feet and would likely not affect any residents in the area. 
The AVWTP has a written Emergency Response Plan for use in the unlikely possibility that an unexpected chlorine release would threaten to spread beyond the plant boundaries. Copies of this plan has been filed with the Local Emergency Planning Committee and the Uintah County/Vernal City Fire Department for their use in assistance if the need should arise. The AVWTP is cooperating fully with all local agencies in their efforts to maintain the safety of all area residents. The AVWTP also has written Emergency Action Plans  
that covers employee actions to contain an unexpected chlorine release within the plant boundaries. 
The AVWTP personnel recognize that well maintained and inspected equipment is one of the best ways to 
avoid a chlorine release problem.  AVWTP has complete written maintenance and inspection 
programs to fully cover the chlorination process at the water plant.  Each ton container of 
chlorine is completely inspected for possible defects or problems prior to acceptance for delivery.  
All AVWTP employees are involved in ongoing training on handling and using chlorine as well as 
complete training in safely containing a possible chlorine release.  AVWTP also incorporates the 
use of constant monitoring equipment in all areas where the chlorine is stored or used.  This 
equipment is designed to sense the presence of chlorine in the atmosphere and give visual and 
audible alarms in the event of an unexpected release.   
AVWTP maintains up-to-date protective equipment assigned to each employee to b 
e used in an 
emergency as needed.  Also complete equipment and kits designed to be used to contain chlorine 
leaks from all areas of the ton containers are kept ready to use if needed. All employees are 
regularly trained in actual use of all equipment and protective gear in order to be familiar with it's 
In the more than 14 year history of the AVWTP, there has been no incident of any type involving chlorine or the release of chlorine into the atmosphere.  AVWTP personnel recognize the great benefits that the use of 
chlorine provides to the production of a safe drinking water.  The AVWTP employees also recognize 
the need for constant vigilance, as well as constant training,  in the use of any hazardous material. Over the last few years we've worked hard at building what we call "Layers of Protection" approach to safety. That means that we routinely evaluate and update our equipment, training and procedures. And now, through the RMP, local emergency responders and other community au 
thorities have become an important part of our risk management process.
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