The Koko Head Shooting Complex will remain closed for at least another month while renovations, repairs and safety improvements continue at the facility, city officials said Monday.

Oahu’s only public shooting range, at 8102 Kalanianaole Highway, has been closed since Sept. 16 in order to complete a $300,000 berm renovation project — namely, installing 3,000 cubic yards of dirt along the pistol and rifle ranges — to reinforce backstops behind the complex’s northern targets. In July a high-caliber bullet hit a dormant firearm slug within the northern berm that ricocheted into the window of a parked car. No injury was reported in that incident.

Also contributing to the ongoing closure was a notice that 12 people, including complex employees and contractors, had received blood test results indicating elevated levels of lead, according to a city-issued statement. Test results indicated the lead levels were well below federal Occupational Safety and Health Administration and medically established levels of concern. Although the levels did not pose an immediate health risk, the employees were relocated out of an abundance of caution, which created a staffing shortage at the shooting complex, according to the statement.

The city Department of Parks and Recreation has reportedly hired an environmental consultant and an expert in outdoor range management, and is working in tandem with the state Department of Health and local law enforcement agencies to review and recommend best management practices for the facility. According to the city, the lead contamination found at the range poses no risk to the general public.

In December the city met with an Arizona-­based firearm range consultant, Kramer One Inc., to review physical and operational improvements needed to maintain safe operations at the shooting complex. Work being done at the site has included roofing, painting, removal of damaged portions of a wall separating the pistol and rifle range, and basic landscaping. In addition, other work includes installation of new signage, more staff training and health screenings, the recycling of spent bullet casings and regular scheduling for daily, weekly and annual cleaning at the complex.

At a news conference held Monday at the site, Parks and Recreation Director Laura Thielen said the city has started “heavy-duty equipment work” to build the dirt backstop, which will, among other things, reduce the chance of ricocheting bullets.

“We’re anticipating this is going to take several more weeks to complete,” Thielen said. Under the current schedule the city expects the archery range to reopen in March, while the public pistol and rifle ranges will open in April.

Thielen said the Honolulu Police Department has been doing work on its own nonpublic “action range,” on the southwesterly side of the complex. In addition, the skeet, trap and silhouette shooting ranges will undergo a review of safety measures and possibly implement use of nonlead bullets to reduce on-site contamination. She added that the city will conduct informational meetings this month with clubs using those three ranges.

Regarding the range employees exposed to lead, Thielen confirmed that two of the workers are full-time city employees and 10 are contractors. She said because Koko Head Shooting complex is an active shooting range, the city is not required to actively remove or mitigate lead at the site.

“We do have a plan for periodic removal of lead,” she said.

As the Koko Head shooting range remains closed, local law enforcement continues to use other locations for training.

“The Koko Head Shooting Complex closure has had minimal impact on HPD’s firearms training because firearms certification for new officers and re-­certification for current officers are conducted at the department’s indoor range at the Ke Kula Makai training academy in Waipahu,” HPD spokesperson Michelle Yu told the Honolulu Star-­Advertiser in an email statement. “Some of HPD’s specialized units, such as the Specialized Services Division and Crime Reduction units, used to use KHSC when it was open. These units are temporarily using alternate locations.”