We invite you to take a tour of the water plant to gain a perspective of the dynamics of the water treatment process. We hope that after your visit you will have a better understanding of how we operate and the committed effort we have of providing the safest water possible to our customers.
Drinking water for the City of Craig is produced at the water treatment plant, which is located at 111 S. Ranney. The city employs a staff of five state certified operators who work on a scheduled rotation to operate the facility. The treatment plant is a Solids Contact/Filtration type designed for a capacity of 7.6 million gallons per day (MGD). The current plant was placed in service in 1983 and serves the city of Craig with an estimated population of 9,300.
Craig's drinking water is supplied by the Yampa River. The Yampa River and its tributaries begin as snowmelt in the Upper Yampa Basin which covers areas North and East of Craig. Situated one mile upstream from the water plant is a intake diversion structure located in the middle of the river. Water flows through a 30" transmission line to the plant where it enters a raw water wet well.
Chemical Addition / Coagulation
Shortly Before the river water reaches the plant, Powdered Activated Carbon is added to control taste and odor problems that may exist. It then goes to the raw well inside the plant. As water is lifted from the raw water wet well and pumped to the Pretreator, several different chemicals are added to aid in the treatment process. Aluminum Sulfate, commonly known as Alum, is used as a primary Coagulant. Particulates, Colloids, and other organic material inherently have a negative electrical charge. With the addition of Alum, which has a positively charged group of ions, particulates are destabilized and no longer tend to repel each other. Very fine, small particles clump together and start forming into larger particles which are called Floc, which appear to the eye as small snowflakes. A Polymer is also added to aid in Flocculation. Polymers assist in neutralizing electrical charges, add weight to the Floc being formed, and consist of long molecular chains which entrap particles in the water.
Flocculation / Sedimentation
After the coagulation process, where small Floc is formed, the water is gently mixed and stirred, to allow contact and collisions between Floc Particles. This process is called Flocculation. These smaller particles gather together to form larger particles. The resulting particles formed will then adsorb sediments, organic matter and bacteria and remove them from the water.
As Floc becomes larger and heavier, they settle to the bottom of the basin. This process of Sedimentation removes almost 90-95% of the particulates in the water. The clear water at the top of this basin is then sent to the filters to remove the small amount of solids remaining.
The City of Craig has a "Solids-Contact" process which it uses to improve the overall solids removal process. These units combine the Coagulation, Flocculation, and Sedimentation processes into a single basin.
Filtration / Disinfection
As the clarified water leaves the pretreator, it is directed to the filter gallery. Just prior to the water entering the filtration bay, a small amount of Chlorine is added to help prevent microbiological growth on the filter media and begin the disinfection process. Filtration is relied upon for the final and complete removal of any suspended matter remaining in the water after coagulation and sedimentation. Each mixed media filter contains layers of anthracite coal, sand and garnet plus an underdrain which supports the media; and collects the finished water which then flows to the clearwell where it is pumped out into the distribution system. As water flows through the layers of the filter media, any extraneous matter is either filtered out or adsorbed onto the filter media. This process is capable of removing very small particles,...down to 2 microns in size. As the filters become clogged, operators can clean them by using a process of reversing the flow of water through the filter media to remove any entrapped solids.
Before water is pumped into the distribution system chlorine is added to the clearwell to assure the bacteriological safety of the drinking water, and to provide protection against possible contamination in the distribution system. The dosage rate is calculated to insure a residual in the furthest points in the distribution system. A sample line is piped from the clearwell to the laboratory to monitor Turbidity, chlorine residual, as well as many other water quality parameters to ensure that the water is safe to drink.
Ph Correction / Fluoridation
During the process of coagulation and flocculation, the water's Ph is decreased. To prevent corrosion in the distribution system the water's Ph is raised to a more alkaline level by the addition of Soda Ash. The City of Craig's finished water has a Ph range between 7.2 and 7.6
Fluoride is also added to the finished water. Fluoride is added to the water to reduce the incidence of dental caries in children. The City's water supply has a small amount of naturally occurring fluoride, but adds additional fluoride to reach the optimum level of 1.0 mg/L.
In an effort to promote public safety, the Environmental Protection Agency has actively enlisted the participation of water suppliers to contribute to the revision of the 1986 Safe Drinking Water Act. These amendments, which were passed in 1996, set new standards for selecting and regulating contaminants. These amendments are a comprehensive effort to regulate contaminants that may have adverse health effects, or pose a significant risk as a public health concern. At the state level, the City of Craig Water Treatment Plant is regulated by the Drinking Water Section of the Colorado Department of Health, which monitors all regulatory testing required by the EPA.
Operators at the Craig Water Plant conduct thousands of tests each year to ensure that the treated drinking water is safe for consumption. These tests determine physical, bacteriological, and chemical constituents present in the water. A minimum of nine samples are taken from representative locations throughout the city each month and are tested for the presence of Coliform Bacteria and Chlorine Residual.
Other tests mandated by the EPA include Lead and Copper, Volatile Organic Chemicals ( VOC's ), Synthetic Organic Chemicals ( SOC's ), Inorganic Chemicals, as well as testing for Radioactive constituents. Microscopic Particulate Analysis, which encompasses testing for Giardia and Cryptosporidium, are used to evaluate the efficiency of the plant's filtration system. Neither Giardia or Cryptosporidium have been found in our City's treated drinking water supply. The City's drinking water consistently meets or exceeds all the standards and regulations presently in effect. Take a look at our 2014 Water Quality Report.
The City of Craig is involved with various measures that serve to conserve drinking water.
Waste of Water
It is a violation of the Craig Municipal Code (Ordinance 565, Article 2, Section 10) for citizens to knowingly waste drinking water. It is also mandated by city code that water service lines to any building be kept free from leaks (Ordinance 565, Article 2, Section 6) as to avoid the unnecessary waste of water.
The City of Craig requires that a water meter be installed for all water service connections to the city water mains ( Craig Municipal Code-Ordinance 565, Article 3, Subsection 1). Water meters are continuously being replaced as older, inaccurate, or dysfunctional water meters are located in the system. Water meter audits are held to discover older meters and inaccuracies in meter readings. When problems with existing water meters are located, new water meters are installed at the expense of the City.
Water Mains and Leak Detection
The City has invested approximately $9,500,000 over the past 17 years (1987-2004) in water main improvements. This large scale replacement program has practically eliminated all the water mains in the City that were known to have leakage problems. The city is further committed to water main replacements scheduled in 2004. Long-range capital plans dictate still further main replacements while the City continues to make repairs on an as-needed basis.
The city has had a complete survey conducted of all water mains by a professional outside service and plans to continue future surveys every 7 or 8 years. The long range capital plan calls for this work to begin again in the year 2013.
Public Awareness and Xeriscaping
The City of Craig encourages the use of water efficient fixtures by all water users. The Uniform Plumbing Code has been adopted for use as a standard for construction and allows that all indoor plumbing fixtures and toilets be of the type that serve to conserve water.
Xeriscaping models have been installed at the Wastewater Treatment Plant for public inspection. Local citizens are encouraged to tour the landscaping for ideas on xeriscaping for their personal use at home. This program has been received well by members of the community and has the added benefit of beautification of the wastewater treatment plant grounds.
Raw water supply is collected from the Yampa River and Fortification Creek. However, the City of Craig also owns an additional 1668 acre-feet of raw water storage located in the Elkhead Reservoir. Elkhead Reservoir is located approximately 5 miles Northeast of the City. Water from the reservoir can be released should drought conditions delete the Yampa River supply. The City of Craig purchased it's share of the Elkhead Reservoir from the Colorado Division of Wildlife in 1991 and has plans to expand the size of the reservoir which will increase the amount of raw water available for municipal use in the future.
The City of Craig currently maintains a total of 24.54cfs of water rights which are collected in the Yampa River intake. These water rights are broken down as 1.33cfs from the Craig irrigation Ditch, 7.0cfs from the Fortification Creek Ditch, 8.29cfs from the Deep Cut Ditch, and 7.92cfs from the Yampa River ( Craig water supply system ).
The City of Craig also installed a water diversion structure in the Yampa River in 1992. This diversion structure effectively backs up the river water into the intake structure of the water treatment plant under low flow conditions. Prior to installing this permanent structure in the Yampa River, water supply to the City was questionable under drought conditions.