Colorado water utilities, pushed to respond to climate change, are giving up their energy-guzzling ways — @WaterEdCO

Workers put finishing touches on Denver Water’s new super-sustainable administrative complex. July 17, 2019. Credit: Jerd Smith

From Water Education Colorado (Jerd Smith):

Colorado’s water utilities, seeking environmental street cred and pushed by citizens, are slashing energy use and carbon emissions.

Denver Water, the state’s largest water utility, uses lots, and lots, and lots of energy every year, some 56 million kilowatt hours. That’s roughly the same amount of power that 6,900 homes would use during that same period, according to the U.S. EPA.

Brian Good, the utility’s chief administrative officer, can cite, almost without limit, one energy use statistic after another. That’s because it is his job to take the utility into a new uber sustainable world, one in which it produces as much clean energy as it uses, a quest in the energy world known as “net zero.”

The utility is on track to hit that mark, system-wide, by the end of next year, according to Good.

The heart of the initiative is the utility’s new headquarters on the west side of central Denver. When it is finished it will generate the electricity it needs and will be able to capture rainwater and wastewater on site, treating it so that it can be reused.

Good and others believe the facility will be the most sustainable facility in Colorado. By operating in a way that reduces climate-damaging greenhouse gas emissions, Good said the utility is helping protect the watersheds that are threatened by a warming climate.

“Our water comes from the environment,” Good said, “so we have to demonstrate that we are doing our part to take care of it.”

Large industrial users, such as water utilities and wastewater treatment plants, are among the biggest users of electricity and, as a result, among the biggest emitters of greenhouse gases.

But that may be changing. Utilities from Grand Junction to Englewood, from Colorado Springs to Boulder and Longmont, are investing heavily in climate-friendly technology.

According to a report by the Colorado Energy Office, industrial operations account for one-third of total energy consumption in the United States.

The state is working hard to change that with new laws and emissions goals. By 2050, Colorado plans to have greenhouse gas emissions slashed to the same levels as 2005, according to Michael Turner, director of commercial and industrial energy services for the Governor’s Energy Office.

Water and wastewater utilities are key players in that initiative, according to Turner. He is leading an effort to help major industrial sectors across the state become more sustainable, and he said water and wastewater utilities, as well as large breweries, are poised to make major contributions to the greenhouse gas reduction effort.

“Denver Water has demonstrated that they want to be at the forefront of the conversation,” Turner said. “But a lot of [utilities] have expansive industrial complexes and they have invested in significant reduction goals and projects.”

Net zero is a sort of holy grail in the sustainability world and Denver Water has been chasing it since 2014.

In 18 months, by the end of 2020, the agency will have replaced its 40-year-old, administration building with a new structure that is net zero and whose inner workings include the ability to use carefully constructed interior wetlands to process rainwater from the roof and wastewater generated on-site so that it all can be reused on the campus. The entire seven-building complex will use nearly 60 percent less energy than the old complex, according to Denver Water spokesman Todd Hartman, dropping from 6.25 million kilowatt hours annually to 2.5 million.

“We need to demonstrate the future of sustainable urban water use but also demonstrate that it is not just water. It’s energy as well,” Good said.

Brian Good, chief administrative officer at Denver Water, is leading the effort to help the utility achieve “net zero,” meaning it produces as much clean energy as it uses. July 17, 2019 Credit: Jerd Smith

Once the complex opens, it will have one of the smallest eco footprints possible with existing technologies, Good said. Several of the buildings will be at least partially buried to help reduce heating and cooling loads. Electricity use will be offset by an extensive solar grid and by the utility’s seven hydroelectric plants. All told, the $204 million project is expected to save about $4 million a year in energy costs.

In some parts of the project, Denver Water has pushed out ahead of technologies and the regulators who oversee them.

One Denver building inspector visited the site several months ago to examine its hyper-sophisticated plumbing system for wastewater reuse, only to leave early because he had never seen the technology being deployed and could not render a decision on whether it had been properly installed, according to Good.

The effort to reuse wastewater has been particularly challenging with state regulations still being written for on-site wastewater reuse systems.

“We thought it would be great to capture the rainwater off our roof before it hits the ground. We also thought it would be great to capture our wastewater and use it to flush our toilets. Neither of these was legal at the time [planning began],” Good said.

Since then the utility secured a water right to capture the rainwater, but regulations governing how wastewater can be treated on-site and reused have yet to be finalized, though Denver Water is working with the Colorado Department of Public Health and Environment to develop them.

“We eventually got a permit to build the [wastewater] system,” Good said. “But we still don’t have a permit to run it.”

Denver Water’s net-zero initiative comes as concerns over climate change and rising greenhouse gas emissions grow.

But it isn’t the only large utility spending big bucks to slash emissions.

South Platte Water Renewal Partners, which processes wastewater for Englewood, Littleton and several small water districts, next month will become the first wastewater utility in the state to capture the biogas emitted from its waste treatment facility, converting it to natural gas, and injecting it into a pipeline for Xcel Energy. The program benefits the environment by reducing the amount of methane, a highly damaging greenhouse gas, released into the atmosphere. It also allows SPWRP to earn a climate credit, which it then sells in a climate exchange marketplace.

Grand Junction was the leader in biogas capture and conversion, using the natural gas to fuel its fleet operations.

The City of Boulder’s utility division too is preparing to capture and convert its biogas, rather than flaring it off, and will likely sell it to Western Disposal, a regional trash hauler, according to Cole Sigmon, the project engineer overseeing the program. Western will use the gas to power 15 of its trucks as part of a fleet conversion from diesel to natural gas.

Longmont is close to finalizing its own biogas recapture facility and Colorado Springs is in the midst of a feasibility study.

In addition, when the new National Western Center is completed in 2025, it will be heated with waste heat captured from the Metropolitan Wastewater Reclamation District’s wastewater collection system.

At SPWRP, much of the work has been driven by the cities, their citizenry, and their joint quest for sustainability, said Dan DeLaughter, data and regulatory program manager.

“Water and wastewater [operations] account for 35 percent of municipal energy bills,” DeLaughter said. “So we are continuously looking for ways to reduce energy use.”

As the solar panels go up at Denver Water’s new complex and the high-tech interior wetlands are built, Good continues to watch the electric meter reports.

Two years ago, he said, even before the complex was complete, the utility almost hit net zero, thanks to the large amounts of power its hydroelectric plants were able to produce that year.

By the end of 2020, Good believes the utility should be able to fully hit the net zero mark.

“It’s going to be close, but we set a stretch goal. If we miss, we’ll keep plugging away. If we hit it, we will set a new goal,” he said.

Jerd Smith is editor of Fresh Water News. She can be reached at 720-398-6474, via email at jerd@wateredco.org.

@COParksWildlife, @DenverWater partnering to improve aquatic habitat on Kemp-Breeze section of Williams Fork

Williams Fork River

Here’s the release from Colorado Parks & Wildlife (Mike Porras):

Beginning Oct. 1, Colorado Parks and Wildlife and Denver Water will begin collaborating on a month-long project to improve fish habitat within a popular stretch of the Williams Fork River near the town of Parshall. Located in CPW’s Kemp-Breeze State Wildlife Area, the section of river to be improved will not close during construction; however, the agencies advise anglers to consider fishing in alternative waters while the work is ongoing.

CPW and Denver Water officials say although they understand October is a prime fishing period along this stretch of the Williams Fork, work would not be possible until streamflow below the Williams Fork Dam slowed to approximately 75 cubic feet per second or less, expected to occur the first week of October.

“Unfortunately, this will affect some fishing trips to this area but anglers should know that the long-term improvements will be worth the temporary inconvenience,” said Jon Ewert, area aquatic biologist with CPW. “This project will turn a very good trout fishery into a great one, so we ask anglers for a little patience.”

“Habitat improvement is one of the most beneficial things we can do to help conserve our natural resources,” said Ben Gallowich, the Kemp-Breeze SWA technician for CPW. “The fish will benefit, the anglers will benefit and this state wildlife area will become an even more attractive place to spend the day outdoors catching trout.”

Ewert says the most significant, short-term impact caused by construction will be visible sediment in the water.

“Due to the type of habitat work that will occur, there will be periods of significant turbidity in this stretch and downstream beyond the confluence with Colorado River,” he said. “And of course there will be heavy equipment throughout the area so it won’t be aesthetically ideal. If anglers choose to fish here they are welcome to do so, but they should avoid machines and construction areas.”

The improvements will include reshaping the channel to enhance habitat diversity for all life-stages of trout. Currently, the river has an overabundance of long riffles. In addition, pools that provided excellent trout holding areas have filled-in with sediment. The habitat project will address these shortcomings.

Completed in 1959, Williams Fork Dam and its power plant sends water and electricity to the West Slope when Denver diverts water. The dam backs up a reservoir of nearly 97,000 acre-feet of water, creating the second-largest water body in Grand County.

For more information and details about the project, contact Denver Water at 303-628-6700.

Raising a Dam — @ColoradoStateU

Here’s the release from Colorado State University (Anne Manning):

Gross Dam spillway design being put to the test by CSU civil engineers

On any given day, the roar of water cascading over a 20-foot-high dam spillway greets visitors to Colorado State University’s Hydraulics Laboratory. Muck boots are required footwear, as water from the spray spreads across the floor, drains into an under-floor reservoir, and flows back toward an outtake pipe for recycling.

The experimental spillway, constructed by CSU civil engineers, is a test bed for an ambitious dam-raising project in southwest Boulder County by Denver Water. CSU engineers are applying their hydraulics expertise to help verify key design and functionality aspects of the spillway, part of the public utility’s planned upgrade to Gross Dam. The reservoir impounded by Gross Dam provides water to more than 1.4 million residents along Colorado’s Front Range.

The engineering team designing the project for Denver Water, Stantec and primary subcontractor AECOM, commissioned civil engineering professors Chris Thornton and Rob Ettema to create a 1:24 working scale model of the heightened dam’s new spillway. The spillway is the only portion of the dam over which water passes.

A project of this magnitude requires a physical hydraulic model, Thornton said.

“Computers have come a long way, but they’re not even close to being able to resolve what’s happening in terms of interaction of forces,” Thornton said. “Turbulence and air entrainment are very hard to model accurately.”

Stepped spillway

Taylor Hogan, a civil engineering master’s student and Hydraulics Laboratory manger, led the design and building of the model, which required close to 500 custom-built pieces. It is called a stepped spillway, which dissipates energy from the water as it flows over the dam. The steps slow the water, trap air bubbles, and allow water to safely descend. Adding to the model construction’s complexity is a slight arch to the spillway profile – mimicking the current profile.

The CSU engineers are now testing and documenting performance, including capacity, flow rate, and ability to handle a major influx of water from a storm or natural disaster. When complete, Gross Dam’s will be the tallest stepped spillway in the United States.

The planned height of the dam necessitated the stepped design. The dam is slated to be raised 131 feet over its current height of 340 feet, increasing the capacity of Gross Reservoir by about 25 billion gallons.

“The expansion will allow Denver Water to add balance and resiliency to its water collection system, which today is at risk of damage from natural disasters such as wildfires and floods,” said Jeff Martin, Denver Water’s Gross Reservoir Expansion Project program manager. “It will also help to manage the greater uncertainty that comes with a changing climate.”

The Stantec/AECOM team specified that the spillway be able to manage extreme high flows they estimate to be possible during the rare occurrence of a massive storm.

“The spillway is designed very conservatively and must perform safely when exposed to extreme conditions,” Ettema said.

Engineering students Taylor Hogan and Blake Biethman stand next to the Gross Reservoir expansion stepped spillway model, Sept. 9, 2019. Photo credit: CSU/Bill Cotton

Remaining work

The CSU researchers are wrapping up the modeling work for Stantec/AECOM to complete the spillway design. The remaining work includes optimizing the layout of the energy-dissipation basin at the bottom of the spillway, to ensure Gross Dam’s design meets safety requirements. Design engineering on the overall dam project is expected to extend through the end of 2020.

Water flows through the distilling basin at the bottom of the spillway model. Photo credit: CSU/Bill Cotton
Gross Reservoir in the mountains to the southwest of Boulder. Denver Water hopes to increase the height of the dam 131 feet, to a new height of 471 feet, to store three times as much water, which it says will help it meet increasing demands and to better weather severe droughts.

Denver Water’s Lead Reduction Program Plan submitted to EPA — News on TAP

A public comment period on the plan to improve public health and protect the environment is open until Oct. 10. The post Denver Water’s Lead Reduction Program Plan submitted to EPA appeared first on News on TAP.

via Denver Water’s Lead Reduction Program Plan submitted to EPA — News on TAP

Remembering the floods of 2013 — News on TAP

Record rainfall six years ago triggered a rare event at Ralston Reservoir. The post Remembering the floods of 2013 appeared first on News on TAP.

via Remembering the floods of 2013 — News on TAP

Colorado’s tale of two seasons — News on TAP

Drought conditions are creeping back into the state after a cool, wet winter and spring. The post Colorado’s tale of two seasons appeared first on News on TAP.

via Colorado’s tale of two seasons — News on TAP

Denver Water asks EPA for rare exemption from Safe Drinking Water Act — @WaterEdCO

From Water Education Colorado (Jerd Smith):

Denver Water is asking the U.S. Environmental Protection Agency for a rare exemption to the Safe Drinking Water Act, the latest move in the utility’s long-running legal dispute with state health officials over how best to keep lead out of its customers’ tap water.

In exchange for the exemption, the water utility, which serves 1.4 million people in metro Denver, is offering to spend more than $300 million replacing up to 90,000 lead service lines.

Though lead isn’t present in Denver’s treated water, it can leach into water as it is delivered to homes via these older, customer-owned water pipes. The contaminant, even in small amounts, is considered unsafe, especially for children.

In addition to replacing the lines, Denver Water has also offered to alter its water treatment protocols, conduct an extensive public education campaign, and provide free lead filters to customers whose water supplies are at risk of contamination.

The EPA will begin public hearings next month to consider the utility’s request and determine whether its proposed approach is as good or better than using an additive called orthophosphate to control corrosion from lead pipes. The state health department, backed by the EPA, ordered the utility to use orthophosphate as a corrosion-control measure last year and gave the utility until March of 2020 to implement the new treatment process.

Within weeks of the state’s order, which came in March of 2018, the City of Aurora, the Metropolitan Wastewater Reclamation District, and the Denver Greenway Foundation sued to stop the order, saying that the addition of orthophosphate to drinking water could cause millions of dollars in damage to the South Platte River watershed and would cause wastewater treatment costs to rise. Denver Water eventually joined the suit. Settlement talks since then have failed to yield an agreement.

Denver Water said it believes the alternate approach it is proposing has merit.

“We would attack the source of the problem and ultimately, at the end of the day, we believe that this could be a more effective approach than adding orthophosphate,” said Denver Water CEO Jim Lochhead.

Graphic via Denver Water

Thousands of Denver-area homes built prior to 1951 are at risk of having lead-contaminated water due to aging service lines. A map compiled by Denver Water shows more than a dozen neighborhoods, including parts of Berkeley, Washington Park and Montclair, as being most at risk. Dozens of other neighborhoods on the map are less likely to face contamination, based on an analysis Denver Water has done which looks at such variables as the years in which neighborhoods were constructed and results of past water sampling.

Denver Water has been monitoring and testing customers’ tap water since 2012, when a routine sampling project showed lead in some taps that exceeded allowable levels.

Since then, the utility has conducted a series of studies to determine the best method for ensuring its water is not corrosive, and had previously offered to adjust the PH balance of its water to mitigate the problem. Up until now, it had also offered to replace a few hundred lead lines a year as maintenance on its system required, leaving any other replacement activity to homeowners and developers.

At that rate, it would have taken up to 50 years before all of Denver’s lead service lines were replaced.

The issue is complex for water providers. Adding orthophosphate is a highly effective way to eliminate lead because it dramatically reduces the corrosion in pipes, making it more difficult for lead to leach into drinking water. But as drinking water is used and then flushed into the wastewater treatment system, the phosphorous must be removed because it causes algal blooms and other environmental issues in waterways. Wastewater treatment operators are required to remove it before they return treated wastewater to streams.

In the seven years since Denver Water became aware of the problem, thousands of Denver residents have continued to be exposed to lead, but the extent of the problem isn’t clear. As part of its monitoring program, the utility has processed 5,600 customer requests for lead testing, with 2,000 of these showing lead levels of at least 1 part per billion, indicating the likely presence of lead service lines, according to Denver Water spokesman Travis Thompson. The Safe Drinking Water Act requires education and treatment when levels exceed 15 parts per billion.

What Denver is experiencing is much less severe than in some cities, such as Flint, Mich., where lead levels in tap water were hundreds of times higher before being discovered in 2015. Still, like other older urban areas, such as New York City and Washington, D.C., Denver must find a way to eliminate the lead or face legal action from the state and federal government.

Tyson Ingels, lead drinking water engineer for the Colorado Department of Public Health and Environment, said his agency would consider the evidence Denver Water presents to the EPA in August before it makes a decision about whether to support Denver’s exemption request. The EPA has so far supported the state’s orthophosphate order.

“Denver is seeking to demonstrate that this alternative is as good or maybe better at reducing lead at customers’ taps. The CDPHE is going to evaluate the evidence when it is submitted,” Ingels said.

Whether the utility will win the exemption isn’t clear. According to the CDPHE, just two exemptions in this area have been granted by the EPA.

“It’s going to be difficult,” said Alan Roberson, executive director of the Washington, D.C.-based Association of State Drinking Water Administrators. “It would have been tough before Flint, and it’s tougher now.”

Denver public health officials said they are supportive of the utility’s exemption request because it offers a more holistic solution to the problem, one that encompasses public health and the environment.

Elizabeth Scherer, air and water manager at the Denver Department of Public Health, said education and follow-up on the problem are a critical part of what Denver Water is proposing. “Denver Water and the city understand that education is a big component of the process and that outreach to non-English speakers and low-income communities will need to occur to make sure folks are comfortable with this approach.”

The EPA will hold hearings next month to gather the public’s input on the issue and is slated to make a decision by October. If the EPA does not grant the variance, then Denver will proceed with adding orthophosphate to its drinking water.