Data increasingly guides water and wastewater treatment operating decisions. Numbers replace sight, sound, smell and dosing-and-retention-time guidance handed down from old-timers. Plants and distribution and collections systems substitute calculations and facts for guesses and gut feelings.

A case in point is Louisville, Colorado, which has two water treatment plants and eight full-time operators for its population of 20,000-plus. The city, between Denver and Boulder, was founded as a coal mining town in the late 1870s. It became a bedroom suburb in the 1950s when the coal played out and the need for living space continued to grow.

Louisville’s Sid Copeland Water Treatment Plant (North) can produce 8 mgd, and the Howard Berry Water Treatment Plant (South) can produce 5 mgd. Both are conventional dual-media sand filter plants using alum as the primary coagulant and chlorine dioxide as a preoxidant for manganese reduction and taste and odor control.

Both plants have undergone major construction and improvements over the last two years. Greg Venette, chief water plant operator, oversees both. “We recently completed construction of a new $3.2 million potable water pump station that had been on the books for 10 years and replaced an old pump station that had been in service since the 1970s,” Venette says. The old pump station could deliver to only one of three distribution zones in the city: the high zone.

“With the new pump station, we added three pumps that can pump directly to the midzone,” Venette says. “Previously, both plants would have to be operating to support all three zones, or valves in the distribution system would have to be adjusted manually every day.”

Bandage fixes fixed

The old pump station was at about the same elevation as the storage tank it was built to pump to. It was a bad design made worse by bandage-type fixes applied over time. Operators Bob Carra, Glen Siedenburg and Herb Trickle are among those who kept things running even when times were tough.

“Lines would air-lock, and pumps would rattle. It was scary,” Venette says. “And it was almost impossible to find spare parts for the pumps.” The new pump station, completed in May 2018, includes modern Aurora split-case centrifugal pumps (Pentair), variable-frequency drives and monitoring equipment. “We also built in pressure relief valves that allow us to download water to different pressure zones in town and back-feed storage tanks,” Venette observes.

The new system provides water to a pressure zone that never existed before. It can send water throughout the city in multiple ways and configurations. The project included replacement and upgrade of the emergency generator (Cummins Power Products) and switchgear (Eaton) and the backwash recycle system.

The project engineer, Rob Anderson with JVA engineering, also figured out how to tie waterlines into the plant cost-effectively to help “jump-start” it under emergency conditions. The emergency interconnect, 200 feet of pipe and a couple of valves, ties the potable distribution line into the backwash influent line to let operators backwash filters using distribution system water and pressure. This provides a backup system so filters can be washed quickly and put back into service without damaging the media or potentially violating regulations.

Better source water

Data-driven decisions also helped at the Louisville Reservoir, one of three raw water reservoirs in the system. For about a decade, the reservoir had problems with algae blooms that led to taste and odor issues and widespread complaints from customers.

“It was a pretty serious issue,” Venette says. “We bought new lab equipment including a Leica microscope, Vortex Mixer (Thermo Fisher Scientific), and centrifuge (Thermo Fisher Scientific) and implemented new testing procedures to better analyze and measure algae in our source water. Operator Thoa Pham became absolutely dedicated to and excels at understanding algae in the lab.” She provides data that helps operators stay ahead of algae blooms.

The operators learned to identify the algae species so they could see the blooms coming. “We looked at algae data for the past 10 years,” Venette says. “We found we could have higher levels of some and it wouldn’t affect taste and odor, but the blue-green algae is what kills us. It causes the most issues.”

Analysis showed that the blue-green algae arrived mostly through one specific supply line. Team members decided to tackle that problem in-house because of their knowledge of the system. “We began a new protocol using copper sulfate, an algaecide, to surface-treat our reservoir from a boat. And we added an in-line injection system that our operators designed and installed to treat our incoming water with copper sulfate.”

Human instruments

The staff also began using barley straw to control algae in the reservoir intake. The results were good. Venette, who holds Class A water, wastewater and industrial wastewater licenses in addition to Grade 4 collection and distribution licenses, says the use of barley straw was based on experience he had in a previous job where he used it in a wastewater lagoon to knock down ammonia and provide nitrification: “We buy it from a local farm and replace it every couple of weeks.”

The water treatment team also added a second SolarBee solar-powered mixer (Medora Corporation - SolarBee / GridBee) to the reservoir to help control algae. They installed an automated water-quality profiler (YSI, a Xylem brand) to provide real-time data on the entire water column. The profiler takes readings at preset depths and includes a probe that measures pH, conductivity, temperature and other parameters.

But instruments can only go so far in measuring subjective qualities such as taste and odor. Venette enlisted the city’s Human Resources Department to help him ask some employees who live in the city to become early-warning taste and odor monitors. They, in turn, enlisted some of their neighbors.

Now the team has both hard data and sensitive human palates supporting efforts to deliver good-tasting water. “We’ve gone two years without any taste and odor complaints caused by algae,” Venette reports.

Collaborative upgrade

In improving its water treatment, Louisville recently completed its first design-build utility project using local engineering and construction firms. The project included both the North and South plants. Cory Peterson, city engineer, directed the effort, which involved replacing existing infrastructure, upgrading equipment and appearances, constructing new systems and resolving nagging issues that are part of any 30-plus-year-old plant. A small sampling of the capital improvement projects included cleaning up old electrical panels, replacing messy, old PLC cabinets, and remodeling valve vaults and adding lighting and ventilation.

The project involved the operations staff and was collaborative from beginning to end. “We completed over 100 individual items called out for resolution in scoping the project,” Venette says. Operators helped identify problems and told the design-build team what was wrong. They put stickers on everything that needed work and kept and prioritized a list so that, as the project became better defined, they had both input and buy-in.

Some items were large and required the support and direction of Kurt Kowar, Public Works director, and approval from the Colorado Department of Public Health and Environment. One example was replacing a drain for the 600,000-gallon clearwell. It went on the design-build list, and when completed, it reduced the time to drain the tank from three to four weeks to three to four days.

Across town

The Howard Berry Water Treatment Plant (South), built in 1993, underwent major upgrades as well. The project replaced the filter media, underdrain nozzles and air scour system. Tube settlers were replaced with stainless steel plates; disinfection switched from chlorine gas to sodium hypochlorite using on-site MIOX generators.

The team also remodeled the HVAC system and installed drying beds for the sludge removed from the sedimentation basin. Together, these improvements made the plant more predictable and easier to keep running smoothly and consistently. “We increased filter runtimes by 12% and now use 2.5% less water for backwashes,” Venette observes.

Under the guidance of Terrell Phillips, superintendent, the staff upgraded the SCADA system from two old Windows XP computers with manual disk backup (and daily prayers) to new SCADA servers, client computers, onsite automated backup, offsite backups and full redundancy for both plants.

Human-machine interfaces had to be completely overhauled to accommodate all the upgrades and changes. The city installed more than $150,000 in new instrumentation, such as turbidimeters, streaming current monitors and chlorine analyzers to replace outdated and obsolete equipment at both plants and laboratories.

“We replaced all of our diaphragm chemical feed systems with new Qdos peristaltic pumps (Watson-Marlow Fluid Technology Group) and integrated them into our SCADA system for flow control and feedback,” Venette says. That change reduced system maintenance and made parts replacement much safer.

The Hach Water Information Management Solution, or WIMS, became the primary database for plant information. Operator Steven Daniels was instrumental in its implementation. “In two years, we went from all pen and paper for recordkeeping to fully digital: computer data entry, automated SCADA data collection and compliance reporting tools,” Venette says. 

“We are now rolling out our new asset management system, Lucity, to replace our old, manual preventive maintenance procedures with a streamlined, digital process.” Operators Jeff Owens and David Cole have shepherded that project along.

Celebrating success

The treatment staff celebrated the upgrades with a Water Day event they hosted for city employees and the public in 2018. It included plant tours and presentations on water use and conservation. Operators volunteered to tell visitors about the facilities. They prepared their own talking points and checked their information in the operations manuals.

The face of the entire operation has changed in a few short years, Venette says: “It took us from a conventional operation to a front-running, optimized, progressive team dedicated to sustaining health by removing water’s impurities through positivity, dependability and data-driven decisions.”

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Embracing continuous improvement

Businesses and government units like to say they go beyond complying with environmental laws and regulations. Yet few yardsticks are available that measure what that really means.

However, Colorado has developed an environmental compliance measurement. It’s a structured approach to improvement called the Environmental Leadership Program (www.colorado.gov/pacific/cdphe/environmental-leadership-program).

The ELP defines what “beyond compliance” means and provides measurable standards by which organizations that voluntarily exceed compliance with state and federal environmental regulations can operate and be recognized.

The ELP has three levels: bronze, silver and gold. It offers benefits and incentives to member organizations that exceed requirements. Greg Venette, chief water plant operator in Louisville, discovered the ELP last year while looking for recognition for his staff’s efforts to excel. He signed up and got started.

The ELP sees a quest for continuous improvement as a part of an organization’s new culture. Venette says that’s the culture his staff members embraced when they began using data to drive decisions. In Louisville’s first year as an ELP member, the team achieved the bronze level; this year they were awarded the silver.