Typical winter weather in the state led to questions directed at Nordic Aquafarms from the city Planning Board this week, particularly about stormwater.

In response to some of the concerns, Nordic representatives focused on the "living document" nature of stormwater and erosion control plans presented Sept. 4.

Maureen McGlome of Ransom Consulting laid out stormwater plans that include sand filters, green roofs, permeable pavers and grass underdrains at various locations on the Route 1-adjacent site near the Belfast-Northport line.

The in-ground filters — sand and grass underdrains as well as pavers — help reduce the temperature of the surface water runoff from roofs and parking lots, McGlome said, before it is released.

Planning Board members asked about snow removal over the pavers — which don’t function if clogged with salt or dirt — as well as how runoff will function when the green roof is frozen.

McGlome said a maintenance contract will include regular cleaning of the pavers to prevent clogs. Nordic Aquafarms Project Director Ed Cotter added the pavers will be cleared of snow by plows, but no sand or salt will be put down in the parking areas covered with pavers. He noted the pavers were used at bus stops in Connecticut and there have been few problems with snow and ice, including slipping pedestrians and vehicles.

Another concern about using the green roofs as stormwater treatment is freezing. During warmer months, the green roofs are designed to collect rainwater in large plastic planting boxes filled with vegetation, McGlome said. The water collected is taken up by the plants and any overflow is picked up by a scupper system.

“I don’t necessarily know the answer to what might happen in the winter,” McGlome said.

Providing professional guidance for the Planning Board, Mandy Oliver of Oliver and Associates said “big frozen chunks” atop several roofs could be an issue in the winter. She speculated warmth from the building below might help prevent freezing, therefore maintaining the stormwater treatment qualities.

“But I’d need to know a lot more about it first,” Oliver said.

Overall, she said, the plan appears to meet city requirements.

“The standard is met but as changes are made, so will the model,” Oliver noted, later adding, “It’s complex and it’s going to change.”

She and McGlome both emphasized the complexity of the design with multiple subsurface treatment systems. Oliver said she used to have reservations about sand filters and grass underdrains freezing in the winter but research has changed her mind.

“They’re proven to quickly defrost,” she said.

Oliver also noted Nordic could have proposed a less expensive design with large sediment ponds often seen with large developments, but said the company “didn’t cheap out.”

Christopher Hyk said during the public comment portion of the meeting that there were problems with frozen drainage at Capt. Albert Stevens School that backed up water into neighboring basements.

“This (design) is very glamorous and I’m sure it would work great in Florida,” he said. “But if it takes out Route 1, you’ve got a problem. If it goes on Mabee/Grace, you’ve got a problem.”

The Mabee/Grace property is located directly across Route 1 from the planned site.

Oliver concurred there is likely to be more total runoff from the site, but the stormwater plans “show they’re not exceeding the peak discharge” currently coming from the property, which is the standard that must be met. The below-ground retention areas allow a slow release of heavy rains, she said.

Director of Codes and Planning Wayne Marshall asked if required inspection reports would be submitted by a third party directly to Maine Department of Environmental Protection and if the reports also could be submitted to the city at the same time. McGlome confirmed.

“The (property) owner usually asks to send it directly to the DEP, or the owner can send it to DEP,” she said.

Marshall added the issue to his list of follow-up requirements that will be addressed by the Planning Board at a later date, along with the questions about the green roof serving as stormwater treatment surface in the winter.

Speaking about erosion control plans during the construction phase, Andy Johnston of Atlantic Resource Consultants said his plan also “is very much a living document” that is subject to change after construction begins. He said the plan is reviewed, evaluated and adapted each day, based on what is uncovered. Shawn Shelley of Gilbane Construction confirmed his company takes responsibility for carrying out the plans.

“There’s going to be changing conditions on the site,” he said.

Planning Board acting Chairman Declan O’Connor broke into the presentation to point out the construction calendar needs to be corrected.

“You’re not starting in September,” he said.

Cotter said the new construction start date is expected to be in April 2020, when the ground is no longer frozen.

“The idea behind the plan is that we’re always covering the native soils regardless of the weather,” he added.

Johnston said the erosion control plan has been broken down into nine phases because of the size of the project. If it chose to do so, Nordic could have proposed stripping the site completely, regrading and starting from scratch, he said, but the company has decided to take a slower approach.

Much of the existing soil is clay, which is not suitable for supporting the large buildings, Cotter said. Trucks will enter the site loaded with appropriate soils for construction and leave with the clay soils, reducing traffic entering and exiting Route 1, he said.

“We are fortunate to have an entrance on a state road so we can avoid (truck traffic through) neighborhoods,” Cotter said.

Information about construction around placement of the intake and outflow pipes is not yet available, Cotter said, because Cianbro — the company contracted for the work — doesn’t “have a full plan yet.” He assured Planning Board members he would contact Cianbro the following day for an updated timeline for the plan.

Oliver again offered her professional opinion and said the plan as proposed is satisfactory.

“I think the plan is reasonable,” she said, later adding, “ … the key to success is flexibility. … The plan is a reasonable approach but it's the execution that’s important.”

Oliver said she recommends the city have its own inspector regularly at the site and to not rely on state inspectors. City attorney Bill Kelly concurred and said, “less is not better. … The more local voice you have there, I would encourage that.”

There was no public comment on erosion control. Marshall, as the meeting wrapped up, spoke about the Whole Oceans project — recently approved by Bucksport’s Planning Board in a single meeting — saying, “It speaks to the level of detail we’re doing here.”