Your Rates at Work

One of Denver Water’s most important responsibilities is to deliver you high-quality water, day or night.

We’re aggressive about replacing and rehabilitating pipes and conduits, some of which are more than a century old.

We replace or rehabilitate pipes and conduits for a variety of reasons, including repairing or avoiding main breaks, replacing corroded pipe, alleviating water quality problems, increasing fire hydrant flow, and improving overall water delivery.

With more than 3,000 miles of pipe in our system, replacing and rehabilitating them is a never-ending job, and one we cannot overlook.

In 2011, we spent more than $11.3 million on:

• Replacing, repairing or installing more than 17,300 feet of treated-water conduit, which are pipes that are 24-inches in diameter or greater. Conduits form the backbone of Denver Water’s treated water distribution system.
• Replacing more than 55,000 feet of pipe.
• Rehabilitating about 50,000 feet of pipe.

In the next decade, Denver Water plans to spend about $120 million on treated water storage tank projects. These projects are so massive — and so important — that it often requires an impressive amount of coordination and skill just to install the concrete floor.

The new Lone Tree Basin No. 2, for example, will be a 10-million-gallon concrete reservoir that stores treated water. The circular tank is next to another tank that was constructed in 1983. Treated water reservoirs provide emergency storage, equalize treatment plant production despite varying daily customer use patterns, provide water to fight fires, and reduce pressure surges through pipes.

Since the first Lone Tree basin was built in 1983, the population served by the facility has grown. Without the additional storage tanks, Denver Water would have to install larger pipes and build additional pump stations, among other projects, in the southern part of the service area to meet future water demand.

Building just the floor of the new tank required so much concrete that more than 120 trucks hauled concrete to the site in one day. Crews will continue working on the walls and roof of the tank to finish the entire project by the end of 2012.

Lone Tree’s Basin No. 2, which will cost about $10 million, will be followed by replacement projects in Wheat Ridge, Centennial and Denver, as well as new tanks for the recycled water system and the Marston and Moffat treatment plants.

Each year, Denver Water collects more than 10,000 samples and conducts nearly 50,000 tests to ensure your water is as clean and safe as possible.

Treating water is an expensive but worthwhile process, accounting for about $15 million annually in operating costs, materials, supplies, routine maintenance and other expenses. Every dollar of that amount goes toward making sure the water that arrives at your house is perfectly safe to drink.

Our state-of-the-art treatment plants ensure your water meets or exceeds all regulatory mandates. Drinking water is regulated through the Colorado Department of Public Health and Environment and the U.S. Environmental Protection Agency.

So next time you’re thirsty, turn on your tap and enjoy clean, filtered Rocky Mountain snowmelt!

On a snowy winter weekend, it’s not unusual to see fire hydrants crushed by sliding cars. But, even in the summer, errant cars still ram into hydrants.

Denver Water owns and maintains more than 19,200 fire hydrants stretching from County Line Road to Green Valley Ranch. And the in-house hydrant mechanic crew is responsible for all of them, repairing or replacing problem hydrants as soon as possible, making sure the hydrants are in top-notch condition when they are needed.

Denver Water has hydrants that have been providing fire protection for the city well before Denver Water was ever established. Some of the oldest hydrants, from the 1880s, still work just fine.

In 1919, a year after Denver Water was formed, a Denver Water engineer designed the Denver Municipal Water Works model of hydrants, which was built in-house for the next 60 years. But replacement parts became too hard to find and the hydrants became too expensive to build, so Denver Water started buying modern models from outside vendors.

Because a new hydrant can cost upwards of $1,000, crews often reuse parts from their on-site storage, aptly dubbed the “hydrant bone yard.”

Still, hydrants wear out beyond repair, and cars often obliterate them. Each year, Denver Water replaces several hundred hydrants, ensuring vital fire protection is there when it’s needed.

As part of our routine maintenance, Denver Water reconditions sections of our water system.

Over time, pipes develop sediment and mineral deposits, such as rust and calcium. Periodic flushing of the mains removes most of this deposit, but eventually, the pipes must be scraped and relined with a thin coating of cement mortar. Rehabilitating the pipe protects it from corrosion, maintains water delivery to homes and businesses, and supports essential fire protection.

In 2011, we’re relining pipes in the Washington Park and northwest Denver neighborhoods. By October, we’ll have relined roughly 50,000 feet of pipe at a cost of $3.7 million.

Pipes cannot always be rehabilitated; sometimes they must be replaced. But depending on the situation, rehabilitation costs are 10 to 40 percent less than replacement.

Denver Water goes to great lengths to make sure water is delivered to customers safely. That’s why we regularly inspect pipes and conduits to catch small problems before they become big ones.

Recently, while testing Conduit 94 — the major pipeline that caused a sinkhole under Interstate 25 in 2008 — engineers found a 16-foot section near Willis Case Golf Course that needed to be replaced immediately, before summer irrigation season began.

Now crews are moving forward with the $153,000 replacement project, helping ensure that the 66-inch-diameter pipe, one of our most important transmission lines, will continue delivering much-needed water to customers.

When Conduit 94 was installed in the mid-1970s, crews used pipe that was made with pre-stressed wires and a thin steel cylinder encased in a concrete core. Since then, because of manufacturing defects, that type of pipe has caused problems throughout the country. Though the break under I-25 was caused by a major pressure surge and not by a loss of structural integrity, Denver Water still keeps a close eye on Conduit 94 and replaces sections of it with steel when necessary.

Being proactive by conducting these kinds of inspections not only keeps our delivery system strong and safe, but also helps us keep costs down. Instead of replacing an entire pipeline at once — a pricey endeavor — these inspections help us target problem areas that need to be repaired or replaced, saving us time and money.

Denver Water crews are working hard to prevent a pesky water weed from causing problems in Marston Reservoir.

Milfoil is an invasive nonnative aquatic plant that thrives in the shallow water at Marston, which is located southwest of Denver. The plant roots in the reservoir floor and grows to the surface where it creates dense mats that look a bit like floating fern.

No one is quite sure how milfoil was introduced to the U.S. in the first half of the 1900s, though experts theorize it was from discarded aquarium water or a ship’s bilge. One thing’s for sure: As welcome as milfoil might be to goldfish in Europe or Asia, it can cause taste and odor problems at Marston, which are difficult to remove once they get into the water.

Because milfoil isn’t present in the closest upstream reservoirs, it’s not clear how it ended up in Marston. It’s possible it hitched a ride with visiting waterfowl.

The pesky plant first became an issue in 1996 when Marston experienced an abundant taste and odor problem. Since then, Denver Water has been trying to rid the reservoir of milfoil. So far, the most effective method is rather old fashioned — draining the reservoir, scraping the bottom and removing the top 6 inches of soil.

It’s by no means an easy process and requires coordination from a variety of Denver Water departments. Beginning late last fall, the reservoir was partially drained. In late January, crews started bulldozing the soil, working from the center out.

Because the reservoir needed to be clear of debris in order to begin filling by April 1 for irrigation season, operators then stockpiled the scrapings at different locations above the shoreline to await final disposal.

Crews removed an estimated 25,000 cubic yards of dirt, which equates to a pile of soil 15.5 feet high across a football field.

Because milfoil regrowth is almost inevitable, Denver Water will keep an eye out for the pesky weeds to return. Projects like this ensure Denver Water can continue with its most important mission: supplying customers with high-quality water all day, every day.

Denver Water is installing the backbone infrastructure for recycled water delivery on the northeast side of its service area.

Conduit 302 will deliver recycled water to north Stapleton, the Rocky Mountain Arsenal, and the Montbello and Gateway Park neighborhoods. During the next decade, crews will extend the conduit to Green Valley Ranch and Denver International Airport.

Recycled water is wastewater treated to a standard that is suitable for irrigation and some commercial and industrial uses. Denver Water owns and operates the largest recycled water system in Colorado.

Conduit 302 will allow Denver Water to triple the number of recycled water customers and expand its recycled water service area by roughly 25 percent.

Crews began installing the conduit in fall 2010. It starts as a 36-inch pipe and narrows to a 30-inch pipe as water demands decrease toward the east. The entire project, which includes more than six miles of conduit, should be complete by fall 2011. And at $10 million, it’s one of the most expensive capital projects on Denver Water’s books this year.

The conduit begins at East 33rd Avenue and Boston Street and will end at East 56th Avenue and North Chambers Road. To get there, though, the pipe must be tunneled underneath nine busy intersections and railroad crossings, and installed around sewer pipes, telephone lines, gas mains and other underground obstacles.

Once Denver Water extends the conduit to Denver International Airport, expected to be completed in the next decade, it will provide recycled water for rental car companies’ car washes, the airport’s central cooling plant and irrigation needs.

When a train chugs along above ground, Denver Water’s infrastructure underground bears much of the weight.

With more trains on the way, there’s a lot of work ahead to make way for RTD’s FasTracks project. Denver Water has an annual vault replacement program, but for the next couple of years, it will be dominated by preparing for RTD’s FasTracks project. FasTracks will add 122 miles of light rail and commuter rail to RTD’s services.

Denver Water spends roughly $2 million each year upgrading and relocating vaults as part of its vault replacement program. Vaults are underground rooms that contain equipment to control the movement of water through pipes. The valves in old vaults are manually operated, but Denver Water is working hard to remodel them into electrically controlled centers that can be operated remotely and more efficiently.

FasTracks also is keeping Denver Water busy encasing conduits with a protective steel casing to shield those pipes from the weight of the new light rail cars. Projects like this take millions of dollars, and hours and hours of coordination, but if everything goes well, customers will continue to receive the high-quality water service they’re used to.

One of the hardest things about finding a leak is listening for it. Was that hollow swooshing the sound of a sprinkler running? A washing machine filling? Or the sound of a leak that’s causing water waste and potential damage to surrounding infrastructure?

Each year, a four-member Denver Water crew surveys roughly 500 miles of pipe, searching for sneaky leaks that have yet to gurgle up from the ground.

Finding leaks is like solving a big audible puzzle. Sometimes, when they’re searching for leaks in busy urban areas, the crew will have to return late at night so they can concentrate on the sound of the leak without the interruption of car horns and diesel engines.

One of the goals of Denver Water’s leak detection program is to survey the entire distribution system — which has almost 3,000 miles of pipe — and pinpoint leaks to help Denver Water crews repair the problem spots.

Finding those nonsurfacing leaks cuts down on expensive emergency main breaks, identifies weak pipes, reduces excavation costs and curtails water waste. In 2010, the crew surveyed more than 750 miles of pipe and pinpointed more than 100 leaks.

Since the 1996 Buffalo Creek Fire and the 2002 Hayman Fire, more than 1 million cubic yards of sediment have washed into Strontia Springs Reservoir, limiting the amount of water storage available in the reservoir and creating water quality problems for the downstream treatment plants.

To combat those problems, we began a major dredging operation in late summer that will remove 625,000 cubic yards of sediment – enough to cover a football field to a height of 200 feet – from the bottom of Strontia Springs Reservoir and pipe it down Waterton Canyon to our Kassler complex, where the sediment will be temporarily stored.

The $30 million project, which will be paid partially by Aurora Water because it owns a 15 percent share of the reservoir, may extend into 2012 if crews are able to pull more than the planned 625,000 cubic yards of sediment from the reservoir.

In the fall, Denver Water and the U.S. Forest Service announced plans to equally share an investment of $33 million, over a five-year period, in restoration projects on more than 38,000 acres of National Forest lands.

Recent wildfires and the state’s 3 million acres of pine beetle-infested forests have emphasized the need to protect forest health. This partnership will accelerate and expand the U.S. Forest Service’s ability to restore forest health in watersheds critical for Denver Water’s water supplies and infrastructure.

Forest thinning and other wildfire fuels reduction projects will take place around and upstream of Denver Water reservoirs. Restoration also will help the forests become more resistant to future insect and disease, reduce wildfire risks and maintain habitat for fish and wildlife.

The average residential household will pay a total of $27 over the course of the five-year project to cover Denver Water’s portion of the plan’s proposed costs.

Every year, Denver Water continues to expand the recycled water system. The recycled water treatment plant opened in 2004 to provide industrial and irrigation customers — those who don't need drinking water — with high-quality recycled water.

By recycling treated water from Metro Wastewater’s plant, we’re freeing up drinking water for other purposes.

Once the recycled water distribution system is complete, expected in the next decade, our recycled water system will free up enough drinking water to serve almost 43,000 households. In 2010, we revised our recycled water master plan, and we expanded our recycled water system to serve irrigation customers, including:

• East High School grounds
• Sixth Avenue median, between Uinta Parkway and Roslyn Street
• Ulaanbaatar Park in Lowry
• Fifth Avenue median, from Roslyn Street to Quebec Street
• Stanley British Primary Soccer Field in Lowry
• Montclair Recreation Center Playing Fields
• Westerly Creek School grounds

And in 2011, we plan to add the Rocky Mountain Arsenal to our recycled water system. The arsenal, now a natural area, needs the water to fill lakes and to benefit wetlands.

There’s one sure thing about working in Corrosion Control.

Rust never sleeps.

Every day, pipes get a bit older, a tad rustier — a little more likely to break. And it’s the job of Denver Water’s Corrosion Control department to find the pipes in the worst condition and put them on the replacement list before they break.

The employees in Corrosion Control visit almost every main break and leak to study the pipe and figure out why it broke. How fast was it rusting? What was the soil like? Had the pipe been damaged? Did freezing temperatures damage the pipe?

They track more than 4,000 testing sites to measure a pipe’s DC voltage. Those measurements then help Corrosion Control calculate the rates of corrosion and decide which pipes need to be replaced before they cause major damage. Corrosion Control also works with Denver Water’s hydraulics department to decide which pipes need to be rehabilitated with cement-mortar lining.

Denver Water leads water utilities of its size in the corrosion control department. Many other utilities don’t have a corrosion control plan — they see main breaks as a cost of doing business and make little effort to prevent them. But ignoring that maintenance can get expensive and dangerous, which is why Denver Water strives to prevent breaks from happening before it’s too late.

Crews are in the middle of a two-year, $17 million project to install a new hydro turbine and expand and repair the outlet works at Williams Fork Dam.

The dam’s outlet works, where operators control the amount of water flowing from the reservoir into the river, was installed during the dam’s original construction in the 1930s. Making repairs to the building’s aging electrical and mechanical systems, as well as to the 50-year-old valves, will bring the outlet works up to current state standards and help it run more efficiently.

Crews also will install a new 0.5 megawatt hydro turbine, which will increase the power plant’s generating capacity to 3.6 megawatts — enough electricity to power more than 3,000 homes. The new turbine also will allow Denver Water to generate electricity during reduced winter flows, when the water level is too low to generate power with the current largesize turbine.

The original dam at Williams Fork Reservoir, located about 20 miles west of Granby, was built in the 1930s. In the mid-1950s, Denver Water doubled the size of the dam, building it up to its current height of 217 feet, and installed a hydropower plant at Williams Fork — making it the first power plant in Denver Water’s system. The construction work began in December 2009 and should be finished in 2012.

Marston Treatment Plant finally got an upgrade.

In 2010, contractors finished a $12 million project to upgrade the 42-year-old filter beds in Filter Plant No. 2 at Marston Treatment Plant. In 2003, Denver Water completed a similar project in Marston’s Filter Plant No. 1 — which was originally built in 1924 — by building a new structure and plant control room.

To complete the work in Filter Plant No. 2, crews had to demolish some of the building’s interior walls, take out the filters’ anthracite coal and sand, replace the filter underdrain systems, remove most of the piping and valves located in the filter gallery, strip old paint, and replace an outdated valve-operating system with a modern electronic system.

The Marston project is just one way that Denver Water is ramping up efforts to make needed improvements associated with an aging infrastructure. Denver Water owns and maintains more than 3,000 miles of pipe — enough to stretch from Los Angeles to New York — as well as 19 raw water reservoirs, 22 pump stations and four treatment plants.

Denver Water’s 10-year, $1.3 billion capital plan details more than 300 projects, including the Marston project, which will help ensure Denver Water continues serving high-quality water well into the future.

Underwater divers spent the summer doing major construction work on one of Denver Water’s oldest dams.

The 105-year-old Cheesman Dam, located on the South Platte River near Deckers, needs important upgrades to maintain dam safety, provide a viable water supply and ensure smooth operations. During the next year, crews are upgrading the dam’s valve system — which was installed when the dam was built in 1905 — and are installing underwater trash racks to prevent debris from clogging the valves.

Crews are installing new control systems and a control building and are updating the dam’s electrical systems. Most of the construction at the site took place underwater using specialized divers. A large working barge was set up on the reservoir while the divers did their work.

Because of the dangerous nature of the work, the divers had to live within a compression chamber mounted to the working barge for 30 days at a time.

Denver Water is keeping the reservoir full and using underwater divers, instead of emptying the reservoir, because we needed the water stored in Cheesman for the summer irrigation season. Cheesman Reservoir is closed to recreation during the project and will reopen next summer.

The two-year $18.3 million project is part of Denver Water’s 10-year capital plan to replace and rehabilitate aging infrastructure, much of which dates back to the World War II era.