Documents filed under Washington’s environmental review process reveal a list of projects in the works for the Mid-Columbia. 

The State Environmental Policy Act, or SEPA, often provides the first look at the mixed-use projects, mini-storage facilities, apartments, industrial expansions, subdivisions and more that are working their way through the various planning departments of Benton, Franklin and Walla Walla counties. 

Here’s a look at projects that appeared in the SEPA register in the past month.  

Three Rivers Convention Center expansion

Kennewick

Knutzen Engineering has submitted plans for a 111,000-square-foot expansion of the Three Rivers Convention Center at 7016 W. Grandridge Blvd. A connected AC Mariott Hotel and a retail building will be built, along with 392 parking stalls. The convention center expansion is expected to start in March 2025 and end in October 2026; the hotel will begin in February 2025 and end in December 2026; and the retail building is expected to start in October 2025 and end in December 2026.

Knutzen Engineering also has submitted plans to build a parking lot at 859 N. Young St., to the west of North Young Street, to help displace the parking stalls that will be removed by the building expansion and nearby hotel construction.

Columbia Park Marina removal project

Richland

Pacific Engineering & Design PLLC has submitted plans to demolish and permanently remove the Columbia Park Marina at 1959 Columbia Park Trail.

The work will be completed using a work boat in the river and land-based equipment including an all-terrain truck crane, forklift and excavator.

The removal includes taking out roof sections, 13 boat lifts, the pump-out station, five gangways, tires and dock sections. The dock pilings will be cut off two feet below the river bottom and removed. The concrete sidewalks near each dock entrance, gangway abutments and the transformer pad will be demolished, and river rock will be placed in the areas where the concrete was removed.

All signage will be removed. The no-wake buoys and floating sign will also be removed, and divers will search the river bottom for demolition debris for removal.

Project Sequoia

Walla Walla County

Kimberly Burgess has submitted plans to build a 2,693,000-square-foot mineral wool insulation production facility east of Sundance Road and about one mile north of the Highway 12 and Attalia East Road junction. The facility would be built over three phases through approximately 2041. Total development on site at full buildout would be about 185 acres of the 250-acre site.

Hermelinda Sierra short plat

Benton County

Hermelinda Sierra has submitted plans to short plat a 5.92-acre parcel at 1709 S. Gum St., Kennewick, into four lots.

Rizin short plat

Benton County

David Rizin has submitted plans to short plat a 0.53-acre parcel at 201 E. 16th Ave., Kennewick, into two lots.

Koskiniemi grading

Benton County

Owen Koskiniemi has submitted plans to grade 1,200 cubic yards south of the intersection of Badger Road and 855 PR SE to construct a single-family home.

Tactical Cleaning

Benton County Clean Air Agency

Tactical Cleaning Company has proposed the permitting of a flare for rail car tank flaring operations at 2579 Stevens Drive, Building D, Richland.

Perma-Fix Northwest mixed waste facility

WA Department of Ecology

Perma-Fix Northwest is seeking to renew its dangerous waste regulations permit to operate the mixed waste facility at 2025 Battelle Blvd., Richland.

Musser Landscaping expansion

Richland

Musser Landscaping LLC has submitted plans to create an additional laydown yard for landscape materials storage and sales at 1770 Buckskin Lane, adjacent to Musser Landscaping’s current operation. The laydown area will be surrounded by a 6-foot privacy fence.

Wilder Road bridge removal, replacement

Franklin County

Franklin County Public Works has submitted plans to remove and replace the existing Wilder Bridge that crosses Kahlotus Creek on Wilder Road near Highway 21, northeast of Kahlotus. The current bridge is a structurally deficient timber bridge 16 feet long and 23 feet wide. It will be replaced with a corrugated steel pipe arch measuring 50 linear feet for safety and maintenance purposes.

Gill Road bridge removal, replacement

Franklin County

Franklin County Public Works has submitted plans to remove and replace the existing Gill Road Bridge, which crosses a dry wash on Gill Road near Highway 260, east of Kahlotus. The current bridge is a structurally deficient timber bridge 16 feet long by 23 feet wide. It will be replaced with a corrugated steel pipe arch measuring 50 linear feet for safety and maintenance purposes.

Oudrhiri boat lift

Franklin County

Christy Batayola has submitted plans to replace planking on an existing ramp at 110 Terrace Drive, Pasco, with grating, install new anchorage and install a standalone boat lift.

Palouse Junction Solar Project

Franklin County

Palouse Junction Solar LLC, a subsidiary of OneEnergy Development LLC, has submitted a proposal to build a 10 MW solar photovoltaic facility on up to 80 acres of unirrigated agricultural and industrial zoned land. The proposed area is along Nordheim Road, east of Highway 395. This land use is allowed with a conditional use permit.

The project would consist of PV modules mounted on a metal racking system, supported by steel piles driven to a depth of 5 to 12 feet below ground. Inverters paired with medium voltage step-up transformers would convert the generated electricity from direct current to alternating current and increase the voltage to minimize power losses during energy collection. The electrical output would be conveyed to a central substation within the project area before being exported to the local electrical grid.

The proposed construction period is six to eight months starting in January 2026, with an operations period of 30 years.

Fischer Dock piles

Pasco

Dave Fischer has submitted plans for the addition of two new 8-inch diameter steel piles and the installation of a new 4-by-64-foot ramp and a 320-square-foot community dock at 10908 W. Court St.

RNA Aviation hangar

Pasco

James Alford has submitted plans for a new 31,002-square-foot hangar and office space at 2901 Rickenbacker Drive. The hangar will be 21,846 square feet with a 9,013-square-foot office.

Road 64 short plat

Pasco

Albert Marroquin submitted plans to short plat land west of Road 64 and south of West Court Street into seven lots and construct frontage improvements along Road 64, establish a new private shared driveway, and extend city utilities to each lot.

Three Rivers Ranch subdivision

Pasco

Robert McLeod of Knutzen Engineering has submitted plans for a 140-lot subdivision south of Burns Road and east of Road 68. The property is zoned high-density residential, and the development will consist of single-family detached homes and will be constructed in two phases. Subdivision improvements will include mass grading, public roads, water, sewer, irrigation and the extension of communication and power infrastructure.

The project also includes the extension of Burns Road and Three Rivers Drive along the property’s frontage. Two public pedestrian pathways are proposed to enhance walkability within the residential blocks.

River’s Edge subdivision

Pasco

Albert Marroquin has submitted plans to subdivide two parcels at 910 Road 64 and 1002 Road 64 into six lots. The project includes constructing frontage improvements along Road 64, developing a new private shared driveway, and extending utility services to each lot.