To the Next Level

An ambitious program to improve water processes and quality wins a Partnership for Safe Water Excellence award for a North Carolina agency
To the Next Level
From left, maintenance mechanic Stephen Long and senior maintenance mechanic James Dodson check over the clarifier blowdown valves. (Valve actuators by Auma Actuators)

Interested in Filtration?

Get Filtration articles, news and videos right in your inbox! Sign up now.

Filtration + Get Alerts

It doesn’t sound like a seven-year program to improve water quality and water treatment processes would make life easier for operators, yet that is exactly what happened at the Jones Ferry Road Water Treatment Plant in Carrboro, N.C.

Improvements generated by the program reduced the plant team’s operating challenges. Owned by the Orange Water and Sewer Authority (OWASA), the plant enrolled in the Partnership for Safe Water and in 2004 began working to optimize performance. That led to the Partnership’s Phase III Directors Award (2005), the Five-Year Directors Award (2010) and the rarely achieved Excellence in Water Treatment Award in May 2011.

 

Conventional process

Built in the late 1940s as a conventional water plant, the Jones Ferry facility was upgraded three times. More sedimentation basins and filters were added in 1962; a new operations building, three more filters and a SUPERPULSATOR clarifier (Infilco Degremont Inc.) were added in 1990; and two additional filters were installed in 2002.

Today, the plant has five sedimentation basins, 10 filters and a capacity of 20 mgd. It serves 70,000 people in Carrboro and Chapel Hill, the University of North Carolina at Chapel Hill, and the University of North Carolina hospitals.

Raw water from University Lake or Cane Creek Reservoir is pumped to the plant and enters the headworks, where it is treated with powdered carbon and alum. Water flows to either the SUPERPULSATOR clarifier or settling basins.

The water is chlorinated for initial disinfection as it flows to the multi-media (sand and anthracite) filters. Fluoride is added to the filtered water and pH is adjusted. The water then flows to a 1.5-million-gallon clearwell for temporary storage and is disinfected via chloramines. Finished water is stored in four elevated storage tanks before distribution to 412 miles of water mains.

Plant equipment includes peristaltic pumps (Blue-White Industries), turbidity meters (Hach Company FilterTrak 660 and SOLITAX), ChemScan analyzer (ASA Analytics), chlorine analyzers (Endress+Hauser), and valve actuators (Auma Actuators Inc.).

 

Major commitment

Steadily improving the process is the aim behind the Partnership, sponsored by the U.S. EPA, the AWWA, the Association of Metropolitan Water Agencies (AMWA), the Association of State Drinking Water Administrators (ASDWA), the National Association of Water Companies (NAWC) and the Water Research Foundation (WRF). It includes more than 200 water utilities committed to enhancing drinking water quality and operational excellence in water treatment.

By joining the Partnership, plants often achieve greater than 50 percent performance improvement without major capital expense. The Partnership provides all the tools plants need to improve water quality and benchmark results against a national database. There are four phases: commitment, baseline data collection, self-assessment, and an optional optimized system phase.

The Jones Ferry plant completed all four. “From 2004 to 2011, we went through the program steps, providing data, writing an action plan and purchasing equipment,” says Ken Loflin, water supply and treatment manager for the plant. “In 2010, we notified them that we had completed Phase IV, and in 2011, we received the award for meeting the optimized system requirements.”

Phase IV includes a rigorous assessment to verify that the plant has met the program goals. Peers from other utilities review the plant’s data and determine whether it has achieved optimized performance. As of late 2011, only nine treatment plants in the country had completed all four phases and received the excellence award.

 

Better operations

For the Jones Ferry Road plant, the Partnership program led to lower water turbidity, lower disinfection chemical usage, and better compliance. While the plant had always met its permit requirements, it did even better after implementing the program.

In 2002, the filtered water turbidity averaged 0.10 NTU; today, the average is 0.03 NTU. The program also improved operations. “It made us more conscious of what was going on with our processes, so we could improve them,” says Dusty Martin, operations supervisor. “We noticed small nuances that most plants wouldn’t think twice about, since they tend to look for big changes.”

The staff reviewed and updated standard operating procedures (SOPs) and made improvements to SCADA alarms and maintenance. “One of the greatest improvements was to optimize the chemical feed dosages to reduce our costs,” says Loflin.

The staff researched the different types of pumps and contacted vendors to arrange demonstrations. The operators and maintenance team worked to remove the old feed system and install the new one.

“We chose a peristaltic pump, which allowed us to feed sodium hypochlorite at full strength rather than dilute it,” says Loflin. “We installed a dedicated pump for each filter, enabling us to better control the feed rate to each filter.”

 

Recycling backwash

Another improvement was reducing the amount of filter backwash. In 2004, backwashing energy cost $2,000. In 2009 after the changes, it cost $750. “This made things easier on operators, as it allowed them to focus on bigger things, such as optimizing the coagulation and sedimentation processes, keeping settled water at or below the Partnership goals,” says Martin.

The plant recycles 85 to 100 percent of the backwash water. “It isn’t a requirement of the Partnership program, but we started doing it to reduce the amount of water we draw from our lakes by about 6 to 8 percent,” says Loflin. “A lot of plants don’t do this because it can create issues like increased turbidity and chemical usage in the treatment train if not handled properly. It can also cause treatability problems with iron or manganese.”

The process takes water from the filter backwash and solids from process basins and sends it to the solids handling facility, where a gravity thickener removes the solids. The solids are then pumped to the belt press for polymer addition and solids separation.

The water is sent to upflow clarifiers before recycling to the head of the treatment process. In 2005, the state Department of Environment and Natural Resources, Public Water Supply, granted approval for OWASA to recycle its process water, so long as the water recycled is less than 10 percent by volume of the raw water entering the plant.

Recycling must be temporarily stopped if the raw water quality inflow exceeds 75 NTU, the treatment and recycled process water exceeds 30 NTU, or the water treatment plant experiences compliance problems.

 

Happy operators

Making all the changes took a lot of work. “Not all the operators were eager about it at first,” says Loflin. “We were already meeting our permit, and now we’re telling operators to go through all these extra steps. Once we asked for their input, they changed their attitude, and they took even greater pride in their work. Plus, they now have bragging rights to say they are the best at what they do.”

Says Martin, “Most of the operators love it now and will joke around with each other. If there’s an operational setback, to turbidity levels for example, they will give each other a hard time about it.”

Operator buy-in and a can-do attitude were keys to the plant’s success. “They take pride in what they do and make decisions on their own,” says Loflin. “They have a great sense of humor, and they’re just cool people.”

A monthly operators’ meeting and a daily morning staff meeting are for airing concerns and discussing the Partnership program. Operators attend the quarterly section meeting of the North Carolina Waterworks Operators Association (NCWOA). “We go to the different plants in our section where we listen to presentations on new equipment and tour the facility, and we do the same for the other plants,” says Loflin.

The plant has preventive maintenance and safety programs and a training program on new equipment. “We do all our training in-house, reviewing the operation and maintenance manuals,” says Martin. “We also have knowledge retention presentations at our monthly operator meetings. If an operator sees a way to improve, he or she will train the other operators on that.”

Each operator gives a presentation or hands-on training each month. The training can cover a plant process, a safety topic, or a piece of equipment, or simply review an SOP. The operator chooses the topic, researches it and presents to the group.

 

Continuous improvement

As part of the Partnership, the plant replaces aging equipment. “In the future, we will continue to look at new technologies and online analyzers to optimize TOC removal and other processes,” says Loflin. “We are not projecting any capacity upgrades until 2030.” The plant will continue with the Partnership and with memberships in AWWA, the North Carolina section of AWWA-WEA, NCWOA, the North Carolina Rural Water Association, and AMWA.

As recipient of three Partnership awards and the North Carolina AWWA-WEA Walter J. Courmon Safety Award (2007, 2010), the plant team is committed to excellence that may lead to even more recognition.



Discussion

Comments on this site are submitted by users and are not endorsed by nor do they reflect the views or opinions of COLE Publishing, Inc. Comments are moderated before being posted.