In May 1955, Wes Brown stood at the door of Miller's Market and welcomed shoppers to its grand opening. Brown was one of Thornton's original residents, and Miller's was the city's first grocery store. It was one of the first businesses in the brand-new Thornton Shopping Center at 88th Avenue and Washington Street, next to a Woolworth's. For the first time, people in Thornton could buy groceries without leaving town. One of the city's water treatment plants carries Brown's name today.
About seventy years later, that same 15.6-acre corner is a flat lot capped with asphalt millings. When neighbors were asked what should replace it, their top choice was a community gathering place built around food, events and dining. The city now has a site with its active cleanup certified, three developer teams and a December deadline. This winter's question is how closely the proposals coming in match that list.
Why the lot had to be dug out first
The center did more than age. Former dry-cleaning businesses on the site left behind a plume of perchloroethylene, a dry-cleaning solvent usually shortened to PCE, in the soil and groundwater. The Thornton Development Authority, or TDA, took title to the property in April 2024, relocated the remaining tenants, demolished the buildings and started digging. The city describes the cleanup as restoring the site's commercial viability.
Excavation began in March 2026. The first step was removing old asbestos water lines, which are regulated separately from the contaminated soil. On September 29, 2026, the city certified that active remediation was substantially complete. According to the City of Thornton's redevelopment page, the work included:
- Excavation of two source areas and the sanitary sewer, at depths of up to 24 feet
- Disposal of more than 24,500 cubic yards of contaminated soil
- Collection and analysis of more than 300 soil and groundwater samples
- Treatment and discharge of almost 70,000 gallons of groundwater pumped out during excavation
- An E-Redox groundwater treatment system in the southeastern corner of the property
- A treatment amendment placed in the main excavation, plus an injection system ready if needed later
- Backfill with clean fill and an asphalt-millings cap brought up to the original grade
"Substantially complete" doesn't mean finished. The city says remaining groundwater contamination on the site, and contamination that has moved downgradient to the southeast, will need long-term treatment and monitoring. Any vapor intrusion issues will also need mitigation. The Colorado Department of Public Health and Environment enforces the cleanup through its Corrective Action Unit. Anyone who wants the technical record can search the CDPHE records review page using the site's EPA ID number, COR000212639.
The same date that marked the end of active remediation, September 29, also moved the developer search into its final stage.
What neighbors asked to put back
The wish list is two years older than the cleanup. In 2024, the EPA's Technical Assistance for Brownfields program, run through Kansas State University, held community sessions for the city. The first was a reuse visioning meeting on April 18, 2024, followed by an online survey, a design charrette that August and a wrap-up session in October. The community engagement report shows how people at the in-person session voted on reuse ideas:
| Reuse idea at the in-person session | Votes for | Votes against |
|---|---|---|
| Community gathering for food such as a co-op or farmers' market, arts, music events, brewery or distillery, like Stanley Marketplace | 41 | 2 |
| Multi-use outdoor community open space | 25 | 0 |
| Small shops and restaurants | 18 | 0 |
| Post office | 18 | 1 |
| Community, arts or multicultural center | 15 | 1 |
| Restaurant, pub, brewery or other entertainment | 12 | 0 |
| Small-scale market or Trader Joe's | 0 | 0 |
| Mixed use, commercial and residential combined | 2 | 37 |
The bundled gathering-hub idea won by the widest margin of anything on the board, with the outdoor open space close behind. The written comments got more specific. People asked for a specialty grocer like Trader Joe's, co-ops and farmers' markets, and sit-down family restaurants. They asked for green space with playgrounds, community gardens and low-water native plantings. Many wanted the post office back, since it had stopped operating on the site. Several said they didn't want gas stations or fast-food restaurants.
They also named places they'd like to see as models. Participants pointed to Stanley Marketplace in Aurora and McGregor Square in Denver most often, and also mentioned Olde Town Arvada, Belmar and the Lowry Beer Garden. They asked for walkable design and for parking that was limited or tucked out of sight.
Housing split people the most. The in-person room voted it down 37 to 2. Online respondents were more open to homes above shops, and the report notes that many residents supported that kind of vertically integrated mixed use. The report's recommendations for further economic study reflect that split. Its list includes grocery, small-format retail, sit-down restaurants, a brewery, a theater or entertainment use and an event hall, along with limited, lower-rise housing. Separately, it recommended outdoor gathering space and a recreation center, library or community center.
In April 2026, City Council approved "The Market at 88th" as the site's interim name. Community input made it the top choice, and the city describes it as reflecting a mixed-use destination built around retail, dining and gathering space.
The three teams drawing it up
The developer search started with a Site Evaluation and Development Framework by Civistruct, presented to Council on October 21, 2025. That was followed by a request for qualifications aimed at both regional and national developers. On September 29, 2026, the TDA advanced three pre-qualified teams to the proposal stage:
- Spark & Halo, Denver. The local entry. In 2025 it was part of a partnership that bought Parkside Collective, a three-building retail center in Aurora built in 2021.
- Colmena Group, Salt Lake City. One of three partners in The Point Partners, the development partner for Phase I of The Point, a large mixed-use community planned in Utah with shopping, entertainment, housing and jobs. Colmena CEO Lance Bullen was also a founding figure behind the SLC Global Logistics Center, a 3,000-acre industrial area in northwest Salt Lake City that broke ground in 2019.
- Sire Group, Irving, Texas. The out-of-state entry from the Dallas area.
So the mix is one Denver-based team, one coming from a large Utah mixed-use project and one from Texas. The Northglenn-Thornton Sentinel reported that each team must submit detailed proposals with renderings, financial information and implementation schedules, and must also present to the TDA.
What the December proposals have to answer
The city's stated goal for the site is short:
"A Walkable, Retail-Driven Community Destination."
Put that next to the 2024 vote counts and you get three tests for each proposal. First, does it include a gathering place built around food, events and dining, the 41-to-2 favorite? Second, is there real outdoor gathering space, which drew 25 votes and none against? Third, how much housing is included, and where? That's the question that split the in-person room from the online survey, and the 2024 report recommended keeping it limited and low-rise.
The grocery store that opened on this corner in 1955 was a first for Thornton. In the 2024 written comments, people asked for groceries again, this time as a co-op, a specialty grocer or a farmers' market, alongside space to sit down and stay.
Dates to watch this winter
- Early December 2026. Full proposals from Spark & Halo, Sire Group and Colmena Group are due, followed by individual presentations to the TDA.
- After the presentations. An internal selection committee reviews the proposals, and the TDA names one developer to negotiate redevelopment terms with.
- Early 2027. The Sentinel reports that the TDA expects to name its developer by then.
- Ongoing. Groundwater monitoring continues, and the city posts its reports twice a year. The most recent one listed on the city page, covering the second half of 2025, was posted February 27, 2026.
If you want updates as they're posted, the city runs Thornton Shopping Center T-Alerts. You can sign up on the Market at 88th redevelopment page, which also links the 2024 visioning documents, the market study and the University of Denver and CU Boulder student proposals for the site.
I'm keeping an eye on 88th and Washington, and I'll be reading the December proposals with the 2024 wish list next to me. If you live nearby and want to talk through what a new market there could mean for your corner of Thornton, reach out to Laura Ruch. Let's Connect.
