DARTMOUTH — If you’ve ever had to go before the Dartmouth Zoning Board of Appeals for a special permit or variance from zoning regulations for a large or small construction project, you may take some comfort in knowing that the town has to comply with the same rules for its own municipal buildings.

Such was the case earlier this month, when town officials had to appear before the ZBA to seek both a special permit and a variance from zoning bylaws to construct a proposed two-story police station at 1390 Tucker Road, the site of the former Gidley School.

The roughly 21,000-square-foot building will be constructed in a General Business district that also sits in an aquifer protection zone, requiring special scrutiny of plans for a 3,000-gallon gasoline storage tank and a fueling station on the site.

The $13.6 million project will be funded by a debt exclusion bond approved by voters in April of 2017, and subsequently endorsed by town meeting members in June of last year. The ZBA’s approval of a special permit and a variance from certain bylaw provisions clears the last major hurdle for the construction project.

At the April 10 public hearing on the case, William Murray of Places Associates Inc., the site planners for the project, presented the town’s case for relief from zoning regulations covering increases in impervious cover and siting the filling station in an aquifer protection zone. Both situations required special permit approval to be obtained, explained ZBA Chair Halim Choubah.

Murray said replacing the demolished elementary school with the new police station would increase the lot’s impervious coverage from 30 percent to 36 percent, but the design of the “low-impact” storm water drainage system would reduce water flow to abutting properties and pre-treat the water retained on site.

Runoff from the front portion of the property would be directed to the storm drains on Tucker Road, while storm water from the rear of the building would be discharged into a drainage swale leading to a retention pond. Murray said the retention pond would prevent any water from flowing toward the nearby Paskamansett River except in the case of a 100-year storm event.

The 3,000 gallons of gasoline would be held in a double-walled concrete tank that is “both bullet- and blast-resistant” and capable of withstanding vehicle impacts without rupturing, the engineer said. The dispensing station would sit on a concrete containment pad that would capture any small spills, and be equipped with a “gas trap” to prevent any spills from escaping the drainage system, he noted.

The dispensing facility would also be protected by two on-site spill kits to contain larger spills, and the drainage system could be shut down completely in the unlikely event of a major catastrophe affecting the storage tank, Murray said.

In the findings included in the special permit approval, Choubah said the 6 percentage point increase in impervious coverage of the L-shaped lot was “not substantially more detrimental” to the neighborhood than the previous non-conforming use of the property, thanks to the low-impact development design of the storm water control system.

The board also determined that the gasoline storage and dispensing facility has been designed to adequately protect both the groundwater on site and the nearby river.

Choubah, an engineer, said the town’s design team did “a fantastic job” on the site plans, which were also reviewed by the Conservation Commission’s consulting engineers before construction conditions were developed for the project.

The accompanying request for variances from height restrictions, the requirement for landscaped islands in the parking areas, and tree-planting provisions for the parking lots were also unanimously approved by ZBA members.

Zoning regulations limit new construction to 35 feet, while the peaked roof design of the new police station would reach nearly 40 feet, Murray said. The other design option was a flat roof, which would likely present higher maintenance costs, and not be as compatible with the architecture of the neighborhood, according to Murray.

Not requiring landscaped islands and mature tree planting in parking areas would improve the effectiveness of the security cameras covering the entire site, improve traffic flow and make winter plowing easier, Murray also noted.

Taken all together, the demolition of the former schoolhouse and plans for the new construction will effectively make the town’s re-use of the property “less non-conforming” than the school that stood there for decades.

Not really addressed during the two public hearings was the potential installation of solar energy panels either atop the covered carport at the rear of the building, or in the open field behind the parking areas. Those options will be considered by town officials at a later date, Murray said.