Ubits May/June 2015
Filtration from the air
Filtered at the source Take a look at this special edition of Ubits to see how Tacoma Water successfully took on the biggest capital project in its history.
In this issue
STEP BY STEP
How filtration works After nine years in the making, filtered water is finally hitting the streets – pipes in the streets, that is. When regulators required in 2006 that water utilities like ours treat water for the parasite cryptosporidium, Tacoma Water knew there would be a long road ahead. After carefully considering the options, the utility decided to upgrade its water treatment operation to include filtration. With nearly six years of planning, testing and design, two and a half years of construction and a $187 million price tag, the Green River Filtration Facility is up and running. Now, the utility provides a better product – and employees involved in the project are proud of the plant’s unique design and function. “This is so exciting because we’re providing customers with water that’s cleaner than it’s ever
been, using a filtration plant that is uniquely suited to handle our water supply, space, existing infrastructure and future needs,” said Gary Fox, a Tacoma Water professional engineer who helped lead the project.
Particle prep Filtering water is not as simple as separating impurities from the water by running it through a filter. There are pretreatment steps before water gets to the actual filtering process. The first step is adding ozone gas for taste and odor control, disinfection, and as an aid to the next step: coagulation. Coagulation happens continued on page 2 Email us. ubits@cityoftacoma.org
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Pages 4-5
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Building a filtration plant
How we got here
Cast of characters
How filtration works when chemicals added to the water are mixed with natural contaminants, causing the mixture to stick together. “The whole purpose of the plant is to remove particles like bacteria, dirt, river silt and other things that cloud the water,” Gary said. “Some of the particles are so small they could pass directly through the filters, so we add chemicals to get them to attach to one another.” The water is mixed to create larger particles that become visible and filterable. That takes place in up to four “flocculation” basins, depending on how much water comes in from the river. Each basin can mix 42 million gallons of water per day, making the daily plant capacity 168 million gallons. Can’t picture that? It’s about what it would take to fill the Tacoma Dome.
Sedimentation
The last step before the water reaches the filters is the sedimentation process. As the water moves through the sedimentation basins, particles drop down. A feature that makes Water’s filtration plant unique is the option to skip the sedimentation process based on the quality of water coming into the plant. With that comes the option to reduce pretreatment chemicals and save on costs.
continued from page 1 “We chose that design – which we call a hybrid – because our water quality changes seasonally. This style of plant gives us flexibility to handle a wide range of water qualities from the river,” Gary said.
Filtration
Finally! The water is ready to go through the filters. Eight concrete boxes totaling 13,440 square feet are filled with 50 inches of anthracite coal and 20 inches of sand for water to flow through, making it 50 to 200 times cleaner than the old process. As the water exits the filtration system, it’s mixed with small amounts of fluoride, sodium hydroxide for pH control and chlorine for disinfection. After filtration, a 108-inch pipe carries the water to two holding tanks, or “clearwells,” that hold a combined 7.9 million gallons of water. The clearwells are filled and drained many times a day as water is supplied to the transmission system.
Controls
“The water quality parameters we’re looking at help us see the whole picture of what’s happening in the plant,” Gary said. “Some of the data is for regulatory compliance, and other data tells us how well and efficiently we’re treating the water.”
Solids
What about all the material that’s filtered out? After going through various basins and pumps, the solid material goes through screw presses to remove any remaining water. Two large screws turn and squeeze out water, which is returned to the filtration process. The resulting material – fill dirt – is sent through a chute into containers to be hauled away. “Tacoma is the first water plant of this capacity to use screw presses to remove water from solids,” Gary said. “Alternative options used at other plants require a lot of space and aren’t as effective. The goal is to maximize our natural resources and reduce the cost of hauling solids away, while providing a high-quality product for our customers.”
Filtration takes about an hour from start to finish. A crew of 17 operates and maintains the plant 24/7. Operators have their hands full, using 70 online instruments to monitor water quality indicators and track over 5,000 alarms.
How it works Ozone Green River Supply Pg. 2
Chemical
Sedimentation
Flash Mix Flocculation
Solids handling
Take a tour
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➐
Now that you know how it works, find out where it all happens
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Center ➊ Operations This is command central. Tacoma
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Basins Pump Station ➍ Flocculation ➐ As water flows through these basins, This building contains five pumps
Water staff work out of this building, including the water treatment plant operators who can control all treatment processes from the control room inside.
particles and chemicals in the water are gently mixed, forming larger particles that can be filtered out further along in the process.
Basins ➎ Sedimentation Facility Large particles separate from the ➋ Chemical Seven different treatment chemicals
water and settle in the bottom of these basins. During some parts of the year, when the water coming from the river is clearer, these basins will be bypassed.
live here in storage tanks. Pumps push the chemicals from the tanks into a number of injection points throughout the plant.
Mix ➌ Flash This is where the water first meets
➏ Filters Water flows through eight filters here, while particles adhere to the anthracite coal and sand that make up the filter material.
most of the chemicals used in filtration. Chemicals are added and rapidly mixed with the water. This process is the first step to condition the particles in the water for filtration.
Pumps
Filters Fluoride Disinfectant pH adjustment
that send filtered water to the Pipeline 1 clearwell. Each pump can process 18 million gallons of water a day.
➑ Clearwells Treated water is stored in these two large tanks just before it flows into the transmission pipelines. The Pipeline 1 clearwell holds 1.3 million gallons of water and the Pipeline 5 clearwell holds 6.6 million gallons.
Handling ➒ Solids The particles removed from the water in the sedimentation basins and filters are treated here. Using various basins and pump stations, water and solids are separated.
Building ➓ Dewatering Within this building, mechanical
P1 Clearwell Pipeline 1
equipment, including two screw presses, squeezes water out of the solids. The remaining material drops through a chute into containers, which are hauled offsite.
P5 Clearwell Pipeline 5 Pg. 3
From start to finish
Building a filtration plant
You’ve probably heard of the figurative challenge of building an aircraft while it’s in flight. Building the Green River Filtration Facility was pretty much the on-the-ground version of that. While operating its current treatment plant, Tacoma Water faced one of the biggest challenges in its history – constructing and testing the new filtration plant at the same site without any noticeable interruption in service to customers. Before breaking ground on the project, Tacoma Water had to kick things off with a big decision: whether to go traditional or progressive in the design and construction phase of the plant. “Design, bid, build” is the traditional process for public projects. Through it, each piece of a project is separate, with little or no crossover between designers, builders and operators. But there was a relatively new – and definitely different – way to deliver a public works project: the general contractor/ construction manager (GC/CM) method. With it, a general contractor is selected based on qualifications early in the design process to collaboratively develop and discuss the project’s cost, schedule and constructability.
Early stages of construction at what will become the Green River Filtration Facility.
Tacoma Water wanted to think different. “We reached out to the few utilities in the Northwest that had employed this approach, and it was apparent that this
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method offered many advantages,” said Deputy Water Superintendent Chris McMeen, who managed the project’s decision process and delivery. After a rigorous preparation process, Tacoma Water received permission from the state to use the GC/CM route – and they’re glad they did. From start to finish, the
Gary Fox and a 108-inch butterfly valve that isolates flow into the Pipeline 5 Clearwell.
benefits have been significant. One of the first challenges to tackle using the GC/CM method was the facility’s layout. With a relatively small site, and one where the existing water treatment facility was already running, putting things in the right place was like a puzzle. The original concept suggested buildings be sited in a way that would require two tower cranes for construction. The builder, Hoffman Construction, was involved early enough to suggest shifting buildings around. The result: the project required just one crane. “That, and other layout revisions probably saved us close to $1 million,” said Project Manager Randy Krueger. Great suggestions also came from employees. Jeff Bolam, water treatment operations supervisor, suggested repurposing a 10-million-gallon water storage tank for cleaning the filters or for use as an emergency water supply. The suggestion replaced the need for a new storage tank and pumps, saving $2 million.
Another savings came from an independent group, who ran two value engineering sessions during design. In that time, experts analyze the design and examine options to bring more value. That was when repurposing the tank was evaluated, along with other ideas and modifications that saved about $10 million, Randy said. “That was a great thing about this process. We all sat down and looked at the design proposals. We have experienced operators here, and everybody had a chance to weigh in,” said Treatment Facility Manager Hilary Lorenz. That’s not to say it was easy. There were challenges, like the tight timeline dictated by drinking water regulations, which required the project be done by April 2014. Knowing that was too aggressive, Tacoma Water negotiated an extension. Tacoma Water broke ground in May 2012, and the plant was substantially finished by December 2014 – a remarkable timeline for a project of this magnitude.
Storage tank where up to 3 million gallons of North Fork Wellfield water can be held before filtration.
“The beauty of this process is that it brings in the right people at the right time to make the right decisions,” said Tacoma Water Superintendent Linda McCrea. “Everybody brought their expertise together. Everybody brought something different to the table.”
Project of a lifetime
Back to that big question: How to tackle the challenge of running an existing facility while building a new one? “You address it head on, early on, in the planning,” Hilary said. “We have two pipes that run water out, so we decided we
testing. Training is helpful, but there’s no match for actually running the plant,” Hilary said. During start-up, all of the systems that were tested individually are used together for the first time. It’s an intense time of learning, reacting and fixing to get things working just right. “There were a lot of late-night meetings and people helping each other,” Hilary said. “We have literally spent the night here, sleeping in chairs. But it was worth it. This is the project of a lifetime.”
What’s next
Roof installation on the Pipeline 1 clearwell, where treated water is stored before it’s sent into pipelines and to customers.
would run both unfiltered and filtered water out when we were ready. We also had to move our chlorine feed system so we could install a new one, move our fiber optics and electrical – all while giving our customers, good, clean uninterrupted water.” To get that plan working, Hilary needed the right team. He had a lot of it from the get go, in the form of some operators who’d worked at filtration plants earlier in their careers and some who’d started up a plant before, which is a rare find. He also hired some key positions, like an engineering instrumentation technician to take care of new electronic systems. With the team in place, Tacoma Water engineers and plant operators ran a pilot plant on site while the new design was underway. Findings from that were incorporated into the facility. But running pilots, thinking things through and preparing is no match for actually running the plant. “That’s what start-up is: Finding the bugs that you didn’t see in performance
Going from one of the few unfiltered surface water supplies in the country to the largest filtration plant in the Northwest comes with a lot of changes. With the filtration plant officially online, the water must be significantly less turbid, meaning that the level of cloudiness resulting from minute particles has to be almost zero. If we go above the mark, we incur a treatment violation and the possibility of having to issue a boil water notice for a product that qualified as clean and
From Tacoma Water Superintendent Linda McCrea On what we do
Our number-one job is public health. We have to make sure that we provide clean, safe water for people to serve their families, to support our economy and to provide for quality of life.
On the decision to filter
Over 100 years ago, a decision was made to select the Green River as our water supply. That was the most expensive option at the time, but the community felt like it was important and it was worth it. That was the same outcome for the treatment decision. We had an option that was probably half the price that would meet the regulation, but it didn’t provide enhanced water quality benefit for the future. Filtration is a very comprehensive solution to treatment. It’s one that very likely will stand the test of time and show that our policymakers today were as insightful as those 100 years ago.
On the team
When we made the decision to go to filtration, it was the same time that I stepped into my job as superintendent. It was a bit intimidating to think that we were going to launch the largest project of our history. On the other hand, I’ve worked in this organization for 35 years . . . I knew we had the best team possible to go forward. Plate settlers, which help with settling particles out of the water upstream of filtration.
perfectly safe just a year ago. “Tacoma Water has provided safe water from the Green River for over a century,” Chris said. ”But now, because of this new plant, the quality of employees operating and maintaining it, and the regulations that govern us all, the water is simply extraordinary.”
It was an exciting time. It could potentially have been very nerve wracking, but it never was for me. It’s been a very positive, high-energy kind of project – one that’s had its challenges. But every step of the way the right people have come together and brought the resources and the knowledge and worked together to solve problems. It has been very energizing and exciting. And now we’re excited to move to the next phase, which is operating the plant.
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How we got here Cause
For a very long time, Tacoma Water was one of the handful of remaining water utilities in the country not required to filter its water supply. Nationally though, filtration was and continues to be the standard for treating surface water. Because of the high quality of the Green River water, we avoided filtration for many decades. Then, in the early 1990s, disaster struck 2,000 miles away.
1993
1994
About 100 people die and 400,000 get sick after drinking water from Milwaukee’s municipal water supply, which contained cryptosporidium. According to the Milwaukee-Wisconsin Journal Sentinel, it was the largest documented waterborne disease outbreak in U.S. history.
Tacoma Water begins testing the Green River for cryptosporidium.
• Tacoma Water begins two-year period of mandatory cryptosporidium testing.
We focus on two treatment options: filtration and ultraviolet light. • F iltering the water would improve taste, reduce the amount of sand and silt entering the pipes, reduce the need and cost for disinfection byproducts, and provide more protection from contaminants like cryptosporidium.
2008
2010
Construction
• T acoma Water recommends the use of filtration to the Public Utility Board and the Tacoma City Council; both approve. • T acoma’s Regional Water Supply Partners approves moving forward with filtration. • D ecision to use General Contractor/Construction Manager approved. • M WH Americas selected for plant design and permitting support. Pilot testing continues; preliminary design starts.
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Decisions
Water concludes two-year monitoring period without detecting cryptosporidium and launches a small-scale pilot program for filtration and UV.
• U V would meet the EPA requirements, including killing cryptosporidium, but doesn’t offer the additional benefits.
Pilot testing
The Washington State Department of Health adopts an EPA regulation requiring treatment for cryptosporidium, which takes effect in 2014.
• B y 1997, we test for it each month.
2007
Options
2006
2011
• P reliminary designs finalized. • H offman Construction Company selected as General Contractor/Construction Manager. • E nvironmental reviews underway. • T hird party value engineering effort identifies numerous costsaving ideas; reduce project cost by $10 million.
2009
• Extensive analyses of risks, costs and benefits of each treatment option are developed. • P ublic outreach begins with goals of informing people and getting feedback on the two options.
2012 • Broke ground. • Project schedules for early work accelerated to take advantage of a favorable bidding climate. • Full construction underway. • Project approximately 20% built.
2014 • Intake improvements completed, along with emergency repairs to a tunnel upstream of the filtration plant. • On Dec. 16, filtered water flows to Tacoma.
2013 • Construction continues; 150 people work at the site each day. • Improvements to Green River intake added to project. • Project 60% constructed.
2015 • Plant operations fine-tuned. • Fully filter all water starting Jan. 15. • Regulatory “switch” from filtered to unfiltered starts May 1.
Cast of Characters Design and construction
Maintenance and operation
Although the ideas and expertise of many employees across Tacoma Water helped make the Green River Filtration Facility project a success, a small team of six led the design and construction. Meet the team:
A team of 17 maintains and operates the filtration facility. Here’s what they do:
Senior Project Manager Randy Krueger helped select the consultant used to design the facility and oversaw construction once it started. Project Engineers Gary Fox and Jason Moline reviewed and approved the contractor’s materials and plans for how to build what was designed, and trained the operations staff on how to use the new systems. Engineering Construction Coordinators Jeff Stone and George Hauser ensured the quality of construction, photo documented the work, tracked schedules and processed payments. Administrative Assistant Shawna Waters set up, tracked and maintained project documents, filing systems and correspondence.
Meet the people who make up the design, construction, maintenance and operation teams
Facility Manager Hilary Lorenz oversees the facility and staff. He’s responsible for safe and effective operations and maintenance, and he ensures water treatment requirements are met. Maintenance Supervisor Wade Green manages maintenance for the plant’s many systems and supports the mechanics and maintenance staff. Mechanics and Plant Maintenance Workers: A team of three (Brett Cook, Chris Cassidy and Mark Brons) keeps the facility in great shape – both mechanically and visually. They troubleshoot and fix issues, and they come up with new ways to improve the plant. Operations Supervisor Jeff Bolam ensures compliance with regulations, evaluates system performance, manages and supports the operators and their 24/7 schedule. Operators: Eight operators (Jozsef Bezovics, Dan McCormick, Renee McMillen, Gary Pederson, Kelly Peters, KC Shankland, Larry Shenk and Aaron Tanczos) continually make decisions to control many interdependent systems required to filter water, ensure disinfection and process solids. Engineering Instrumentation Technician Robert Wang sets up and maintains the many electrical and other systems required to operate the facility.
From left to right: Chris Cassidy, Robert Wang, Brett Cook, Jeff Bolam, Jason Moline, Kelly Peters, George Hauser, Hilary Lorenz, Jeff Stone, Gary Fox, Mark Brons, Randy Krueger and Wade Green. Not pictured: Gary Pederson, Dan McCormick, Renee McMillen, KC Shankland, Aaron Tanczos, Jozsef Bezovics, Shawna Waters and Larry Shenk.
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Tacoma Public Utilities PO Box 11007 • Tacoma WA 98411
$38 million came from low-interest loans from the state’s Public Works Trust Fund
Filtration by the numbers
$72 million came from Drinking Water State Revolving 700,000 Fund
hours
Green River water supply: Part of a 230-square-mile protected watershed in the Cascades Green River: Our primary water source for the last 102 years
102 years
Tacoma Water: 2nd largest water purveyor in Washington
Ubits is a publication for Tacoma Public Utilities employees and is provided as a courtesy to retirees. Jenae Elliott, editor ubits@cityoftacoma.org • (253) 502-8754
PRSRT STD US POSTAGE PAID TACOMA WA PERMIT NO 2
Miles of water pipe from plant to Tacoma: 43 2 pipelines leave the plant with filtered water: Pipeline 1 and Pipeline 5 Original cost estimate to build the facility: $217 million Preliminary cost: $187 million 3 Second Supply partners paid for one-third of the cost of the plant
Construction hours to build the filtration facility: 700,000 30 subcontractors and up to 150 laborers working at one time 25 acres of infrastructure needed to make filtration work
Distance the water travels through the filtration process: 0.5 miles Time it takes to filter the water: 168 25 to 60 million minutes
gallons
Gallons of filtered water the facility can send down the pipes in a day: 168 million Pounds of fine sediment pushed through the water pipes each day before filtration: About 1,000
Pounds of fine sediment pushed through the water pipes each day since filtration: Zero. Zilch. None. Facility operators: 8 Online instruments to monitor water quality: 70 Alarms to identify problems: 5,000 Filtered water is 50 to 200 times more clear than when unfiltered
5,000 alarms
Facility operating since: Dec. 16, 2014 Official completion date: May 1, 2015 Facility’s expected life: 100+ years Number of people Tacoma Water directly serves: 316,000 Number of people served when all wholesale and partner customers are counted: 1 million people
1 million people