The owner of a light industrial park in Kailua’s Kapaa Valley has been instructed by the city to conduct a more comprehensive environmental study for a proposed expansion of the facility.

John King of Kapaa I LLC wants to nearly quadruple the size of the warehouse complex, which dates to the mid-1970s and is adjacent to the state’s largest wetland, Kawainui Marsh.

The company submitted a proposed final environmental assessment, or FEA, to the city Department of Planning and Permitting last year, but the agency recently concluded that a more comprehensive environmental impact statement is necessary.

The agency said the environmental assessment didn’t adequately analyze potential impacts to the marsh and area views. The agency also wanted more information on potential inclusion of noxious industries in a larger park.

"Since the FEA still leaves several questions unanswered, it is clear that an EIS does in fact need to be prepared if this project is to move forward," the agency told Kapaa I in a letter earlier this year.

Kapaa I recently notified the state Office of Environmental Quality Control that it plans to prepare an EIS that addresses the issues.

King, who owns Kapaa Light Industrial Park and All Pool & Spa, could not be reached for comment last week.

King wants to expand the complex from an existing 250,000 square feet of warehouse space to about 910,000 square feet over an estimated 16 to 18 years.

At completion about 35 warehouse buildings and 570 parking stalls would occupy an expanded park.

The land area for the complex would grow to 77 acres from 22 acres, though about 30 acres would remain in open space, including a 15-acre wildlife sanctuary proposed by Kapaa I.

The expansion, according to the developer’s environmental assessment, would help address a shortage of industrial space in Windward Oahu.

The company said it expects likely users of new space could include contractors, automobile sales and service centers, data processing facilities, wholesale and distribution companies, home-improvement centers and other general warehouse and base yard tenants.

The Planning Department said potential impacts from noxious users should be discussed in an EIS. The agency also said there should be more analysis of impacts on the marsh from twice as much heavy truck traffic and changes to view planes.

Robert Harris, director of the Sierra Club Hawaii Chapter, said the marsh is an environmental treasure. "I appreciate the city’s sensitivity to the fragile nature of the area," he said.

The Sierra Club did not submit formal comments to, or take a position on, the developer’s draft environmental assessment.

Charles Prentiss, chairman of the Kailua Neighborhood Board, said the community generally isn’t against adding more space for industrial businesses in Kailua, but some residents have raised concerns.

Prentiss said the main concerns are the lack of a sewer connection to the park and potential impact to the marsh.

The site is off the H-3 freeway along Kapaa Quarry Place next to rock quarry operator Ameron Hawaii and an old landfill. The site also sits above the marsh, which was once the largest inland pond on Oahu.

The expansion site involves three adjacent parcels, including two that are zoned for preservation and would need City Council approval for a zoning change to I-2, or intensive industrial, use. The existing park and some surrounding land is zoned I-2.

Kapaa I said, in its environmental assessment, that the expansion site is on land created from deposits of quarry tailings and municipal solid waste associated with quarry and landfill operations in the valley dating to the early 1950s.

King owned warehouses on about six acres of leased land in Kapaa for many years before purchasing the property and an additional 71 adjacent acres from Kaneohe Ranch in 2003.

The developer said 15 acres of the site will be restored as a protected wetland for wildlife with a public viewing area.

The sanctuary, which is in a design and permitting phase, would include several cascading ponds, and invasive plant species would be replaced with native or adaptive plants to shelter area wildlife.

Among marsh inhabitants are the endangered Hawaiian stilt, Hawaiian moorhen, Hawaiian coot and Hawaiian duck.

Kapaa I also said the industrial park expansion and wetland restoration would improve existing erosion and storm water runoff that pollutes Kapaa Stream and the marsh. A drainage system and storm water detention ponds are part of the expansion plan.

To handle waste water, Kapaa I proposes installing 18 septic systems. The developer said connecting the park to the nearest municipal sewer line 1.5 miles away would be expensive and an inefficient use of electricity to pump a relatively small amount of sewage. Presently there are five septic tanks with leach fields at the industrial park.

The planning department said the EIS should assess whether a catastrophic septic tank failure is possible.