Public Notice

Update of Richfield City Drinking Water Source Protection Plans

April 2011

The purpose of this Public Notice is to summarize source protection issues associated with Richfield City’s drinking water sources.  It is released in accordance with DEQ rules and regulations.  
Geologic and Physical Settings

The principal groundwater system in the Sevier-Sigurd basin occurs in unconsolidated basin valley-fill.  The wells Richfield City uses extend to depths of 850 and 290 feet and obtain water from sand and gravel layers which are interbedded with clay and silt layers.

The Richfield Spring is located in the Flagstaff Limestone along the Elsinore fault which runs along the west side of Richfield. Studies show the limestone is not very permeable and that the flow is a result of fractures of tubes facilitated by the fault, or the fault intercepts a deeper aquifer and dissolution of the limestone by the water has created a conduit to the surface.
Drinking Water Source Protection (DWSP) Zones and Potential Contamination Sources (PCSs)    DWSP Zones are surface and subsurface areas surrounding the Wells and Spring through which contamination above ground may travel through and pollute the Sources.  Four DWSP zones are delineated for each source, except the spring which has two zones.   

Most of the PCSs which exist within these zones are residences, roads, farmlands, businesses and parks.  These PCSs have the potential of using or generating materials which may have the potential to contaminate the Sources.  Examples of these materials include sewage, pesticides, fertilizers, household hazardous wastes, and accidental vehicle spills.  
Susceptibility Analysis

A well Richfield City uses that was drilled in 1998 has proof of 1) a clay layer thicker than 30 feet (actual thickness, 100 ft) existing above its aquifer, 2) this clay layer extends beyond its Zone 2, and 3) it has a grout seal that extends over 100 feet (actual depth, 150 ft) down from the ground surface.  Therefore, its aquifer is classified as protected.  

An older well Richfield City uses that was drilled in 1969 has a similar grout seal, but when the well was constructed, no proof was documented of the existence of a 30-foot-thick clay layer over the aquifer.  However, there is supporting evidence from other sources that such a layer exists and that the aquifer is likely protected.  But until additional data can be obtained, the aquifer is officially classified as unprotected.  

A well Richfield City uses that was drilled in 2003 has proof of 1) several clay layers thicker than 30 feet existing above its aquifer, 2) these clay layers extend beyond its Zone 2, and 3) it has a grout seal that extends over 100 feet (actual depth, 630 ft) down from the ground surface. Therefore, its aquifer is classified as protected.  

The Richfield Spring does not meet the protected aquifer criteria as outlined above.  However, because of the impermeability of the Flagstaff Limestone in addition to the results of several studies and tests conducted on the spring, the professional hydrogeologist who drafted the DWSP for this Source believes the Richfield Spring should be classified as a protected aquifer.  

In each case listed above, the existing impermeable grout seals, low-permeable clay layers above each aquifer, or the impermeability of the Flagstaff Limestone in the case of the Spring, make it very difficult for PCSs to reach each Source’s aquifer.  

Generally, all of the PCSs listed for Richfield’s drinking water sources have hazard controls in place.  Specifically, applicable codes, rules, and/or regulations exist with an associated enforcement agency, Best Management Practices (BMPs) are in place and used by the PCS, physical controls are in place preventing contamination, or the quantity of hazardous material used is negligible.  

Most PCSs within Richfield’s Source Protection Zones have relevant rules and regulations in place, but the applicable enforcement agency may not be able to ensure compliance in all cases.  Therefore, individuals within the Zones are encouraged to be proactive in protecting Richfield’s drinking water aquifers by electing to use and dispose of chemicals and hazardous wastes according to applicable rules and/or regulations.

Due to the high degree of protection of each drinking water source and the low probability of a hazardous material being released in a large enough quantity to contaminate a drinking water aquifer from a higher risk PCS, the contamination susceptibility of Richfield’s wells and spring is classified as low.      
Land Management Strategies

The primary method Richfield uses to manage existing PCSs is by using bill payment stuffers to notify PCSs of their location within the drinking water source protection zones.  In addition to this notification, the City provides information sheets to these PCSs listing BMPs for each type of potentially hazardous material that will help guide each PCS to minimize and/or prevent any potential contamination of a drinking water source.  City maintenance personnel are trained to follow BMPs for each hazardous material they may handle.  The City maintains open communication lines with local agencies that govern other PCSs.

Richfield City will contact future PCSs that locate within its source protection zones, add them the current inventory of PCSs, identify and assess their controls, and plan and implement land management strategies if it is not adequately controlled.         
Drinking Water Source ProtectionPlans

A copy of the complete Drinking Water Source Protection Plans for Richfield City are available from Richfield City upon request, for an appropriate fee.