August 2019 Print Issue BTrenchless C&L Water Solutions Colorado Denver Denver Water Features New Installation Rehabilitation tech United States

Denver Metro Trenchless Projects Accommodate Urban Expansion

A crew works on a lining job for the City and County of Denver

Maier notes that whereas using trenchless isn’t new within the space, inhabitants progress and the presence of corporations specializing in high-tech have been drivers for the rise in development to accommodate improvement, with trenchless being a major factor.

“I feel reputation of the world and a more progressive view on know-how have been elements for the acceptance,” provides Maier, who additionally serves on the board of directors for the North American Society for Trenchless Know-how (NASTT) and has held a lot of positions in the trenchless sector working within the Rocky Mountain region. “A whole lot of engineering consulting companies have hubs of operation in the Denver metro area, and that provides the assets from a technical standpoint to help that.”

He notes a number of the giant municipalities and utilities within the space together with the Metro Wastewater Reclamation District (MWRD), Denver Water and the Metropolis of Aurora have been huge proponents main the charge. He also notes Fort Collins as a prepared adopter of other undertaking delivery methods. Here’s a take a look at a number of the trenchless work occurring across the Denver metro area and some tasks which were completed by numerous utilities and municipalities in recent times.

City and County of Denver

The City and County of Denver has a capital tasks group, Wastewater Infrastructure Venture Management (IPM), that’s liable for increasing and upgrading the Metropolis’s storm and sanitary sewer infrastructure and waterways.

Separately, the Wastewater Administration Division of the City and County manages annual exhausting bid contracts targeted on crucial and preventative sewer lining within the city. For its essential upkeep, the Wastewater Management Division has a program that addresses unforeseen points found by sewer inspection utilizing CCTV that it does in-house. The division has an annual fund put aside for these tasks and rehabilitates strains in many instances utilizing trenchless. Separately, the division performs emergency repairs which might be addressed by its in-house development group.

The Wastewater Administration Division’s preventative maintenance work consists of addressing pipelines which are recognized to be problematic resulting from elements like age, materials sort, corrosion or other failures that need point repairs. These strains are additionally inspected utilizing CCTV before a plan is carried out by the division’s engineering staff previous to contractors being on the job.

“We have now a whole lot of flexibility in our operations because we have now in-house CCTV and in-house development crews to carry out work forward of the contractor to lower the price of lining and probably help get rid of change orders,” says Selena Klosowski, engineering supervisor for the Wastewater Management Division.

Klosowski’s engineering group does design work unbiased of needing to rent outdoors design consutlants for wastewater essential and preventative maintenance. Other work that may be completed by the division’s in-house development crews are manhole repairs and other preliminary work before contractors arrive on the job. As well as, the City additionally performs vac and jet work to wash wastewater infrastructure as a part of its preventive upkeep and to attenuate sewer backups.

Annually, the Wastewater Administration Division does about $3.9 million in relining using CIPP. Beneath its annual contract, the division usually rehabilitates 80,000 to 120,000 lf of sewer pipe together with some storm sewer. That program has been managed by the Wastewater Management Division since 2017.

“Trenchless rehabilitation just allows us to extend the lifespan of our infrastructure with out even having to open reduce to remove and exchange them,” Klosowski says. “Within the Metropolis, open reduce can usually be extra disruptive, time consuming and dear than trenchless methods. We see trenchless as a greatest administration follow as a result of it’s simpler with the finances we now have.”

MWRD Interceptors

Denver’s Metro Wastewater Reclamation District is the wastewater remedy authority for a lot of metropolitan Denver and elements of northern Colorado. The utility serves roughly 2 million individuals in a 715-sq-mile area that features Denver, Arvada, Aurora, Brighton, Lakewood, Thornton and Westminster.

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MWRD declined to be interviewed for this story, but the district, which also performs preventative maintenance, has been lively in rehabilitation work on its interceptor sewers.

In 2016, underneath its Interceptor Situation Assessment Initiative, MWRD’s engineering employees identified 83 pipe segments throughout four interceptors – the Bear Creek, Cherry Creek, Harvard Gulch and Sand Creek Interceptors – and identified severely corroded or broken pipe segments in need of rehabilitation or restore. Two diversion buildings on its West and Southside interceptors have been also recognized as very poor as a consequence of inoperability and a possible security hazard for entrants. The 2017 Interceptor Rehabilitation Venture was initiated in late 2016 to deal with the recognized rehabilitation and repairs. The design and bidding part work was accomplished in-house by engineering employees and MWRD entered into a contract with Insituform Technologies for the development.

Insituform started CIPP insertions in January 2018. Work completed included the next gadgets:

  • Several thousand linear ft of the MWRD’s Harvard Gulch Interceptor Pipe (42- and 48-in. diameter) have been rehabilitated using CIPP.
  • A number of thousand linear ft of its Bear Creek Interceptor Pipe (36- and 39-in. diameter) was rehabilitated utilizing CIPP.
  • Four totally different phases of wastewater bypass methods have been designed, assembled, tested and operated to accommodate CIPP lining actions.

One other undertaking at present in motion, MWRD’s Second Creek pipeline, will allow parts of Aurora, Brighton, Commerce City, Denver, Denver Worldwide Airport and South Adams County to be served by MWRD’s Northern Remedy Plant. The pipeline might be approximately 20 miles long and ranges in diameter from 24 to 60 in. and might be constructed 5 to 50 ft underground. The venture will contain 17 tunnels and the overall contractor, Garney Development, has issued qualifications for hand mining, non-pressurized TBMs, guided auger boring/pipe ramming and pressurized microtunneling.

Denver Water

Denver Water’s collection system covers greater than four,000 square miles and the utility operates amenities in 12 counties. It additionally operates and maintains more than three,000 miles of distribution pipe. Denver Water has dabbled in trenchless in recent times where applicable, in line with the utility’s communications specialist Jose Salas.

In accordance with Salas, in spring 2018, 29th Avenue was partially closed between Sheridan Boulevard and Fenton Road for a rehabilitation venture on a 36-in. steel pipe originally put in in the 1920s as one of the last phases of its Ashland Reservoir Tank Alternative challenge.

Denver Water engineers seemed into sliplining the prevailing 36-in. pipeline with a 30-in. fusible PVC pipe. On the time, the most important PVC pipe Denver Water had used in its system was 24-in., making this the most important PVC strain pipe install so far. It was determined that fusible PVC from Underground Options would adequately provide the move calls for of that system phase whereas providing a brand new non-corrosive asset. The 30-in. pipe was fused and put in by means of a 1,200-ft phase in one week, whereas the undertaking was initially slated to last three weeks. The undertaking was highlighted in a paper and introduced at NASTT’s No-Dig Show in Chicago earlier this yr.

As a aspect notice on Denver Water, the utility made headlines earlier this summer time when it announced a dedication to exchange its remining lead pipes with copper strains over the subsequent 15 years. There are an estimated 90,000 residences within the Denver area that have lead service line connections for potable water and the plan put forth by Denver Water up to now is pending EPA approval.

Metropolis of Aurora

Aurora, Colorado, situated about 20 miles east of downtown Denver, has been one of the lively municipalities within the metro space on the subject of underground development, in response to Maier.

One fascinating venture got here in late 2018 when the Metropolis needed to rehabilitate manholes as a part of rehabilitation work on the Sand Creek Interceptor. In response to Chris Larson, chief operations officer at trenchless contractor C&L Water Solutions, previously-used coatings and high H2S levels had left the interceptor with dilapidated manholes and greater than 60 of them needed to be replaced, some as deep as 25 ft.

C&L was chosen because the contractor on Aurora Water’s Manhole Insert Rehabilitation Part 2 challenge. Larson says Aurora had experimented with the thought of manhole inserts prior to now and was assured within the course of. C&L used fiberglass manhole liners from Giddings, Texas-based LFM, a producer of liners designed specifically to fit inside deteriorated manholes. Diameters of the manhole liners are sized 6-in. smaller than the host manhole diameter. The manholes needing alternative on this undertaking ranged from 24 to 42 in. in diameter.

“The City chose the fiberglass inserts because it needed an inorganic materials that’s not topic to corrosion like concrete,” says Larson.

The set up process involved rehabilitating the benches, putting in the insert and filling the annular area with a flowable fill or urethane grout. The insert know-how gave the City a brand new manhole at a fraction of the fee and disruption.

“On average, it took about three days to do each of these,” Larson says, with the venture taking a complete of about 180 days. “A variety of the manholes had high flows, but thankfully they have been capable of be diverted to parallel interceptors.”

Larson provides the state of trenchless development has been robust for a while across the state of Colorado, noting the Consolidated Mutual Water Company in Lakewood, Colorado, which started pipe bursting greater than 20,000 ft of water pipe yearly in 2010.

“I’d say the larger Denver space appears to be very receptive to trenchless as an entire,” Larson provides. “They’ve been very progressive with rehabilitation packages. If something, it’s slowed down from our perspective. In prior years, we’ve seen some cities doing 100,000-ft tasks every year that they’re now doing each other yr or every third yr. But we’re seeing much more rehab work now in the northern and southern elements of Colorado.”

The Metropolis of Aurora has additionally been lively on the new installation aspect in its use of trenchless development. One such venture is the Fitzsimons-Peoria Stormwater Outfall challenge at present in progress for Aurora Water. This challenge will improve an present storm drainage basin and infrastructure to convey a 100-year storm event in response to current flooding and concrete revitalization.

The job includes a pair of microtunnel drives being completed by trenchless contractor BTrenchless, which has accomplished quite a few trenchless installations throughout the Rocky Mountain area. The primary is a 72-in. nominal ID Hobas pipe that shall be 320 ft utilizing an Akkerman SL74 MTBM. The subsequent drive out of the same pit shall be a 48-in. nominal ID Hobas pipe using an SL51 Akkerman MTBM that will probably be 148 ft.

The undertaking additionally includes two TBM tunnels that may begin this fall, considered one of which is a 54-in. ID Hobas direct jack TBM that might be 240 ft lengthy and a last drive that shall be 96-in. diameter spanning about 280 ft. Those tasks are slated to start in early 2020.

City of Aurora’s Manhole Insert Rehabilitation Phase 2

Metropolis of Brighton

Within the Metropolis of Brighton, about 20 miles northwest of downtown Denver, BTrenchless additionally completed a 660-ft, 72-in. diameter microtunnel beneath the Union Pacific Rail Yard in 2018. The job installed metal interlocking pipe from Perma-Lok for a brand new storm sewer. The undertaking was completed for the town and City Drainage & Flood Control District, which was taking emergency action to alleviate flooding in the space.

Chris Knott, director of enterprise improvement at BTrenchless, notes the high variety of tasks in response to storms within the Denver area roughly five years ago that triggered vital flooding within the area.

“Everyone actually put a eager eye on taking a look at what methods can deal with,” he says. “It’s been loads of upgrading of storm sewers since then.”

North Brighton Outfall Phase II project

Knott adds that past flood management, most of the trenchless tasks occurring within the Denver metro area mirror the developments in infrastructure development across a lot of america.

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“I feel Denver, like most different cities, is at some extent where infrastructure needs to be up to date,” he says. “It doesn’t matter what it is. It’s all been in the floor a very long time, particularly in bigger cities. Not solely are those capacities for water or sewer not adequate, however it’s also telecommunications, for example. Every part needs to be upgraded to match the growth, not just here but in all places.”