Protesters of the land-based salmon farm proposed for Belfast hold signs Thursday night outside of an informational meeting held by project developer Nordic Aquafarms at Troy Howard Middle School in Belfast.

After months of waiting, speculating and often-heated debating about how a proposed land-based fish farm in Belfast would affect Penobscot Bay, Nordic Aquafarms on Thursday night released some preliminary information regarding what it actually might put into the water.

The public information hearing at Troy Howard Middle School in Belfast, attended by around 200 people, was the first held as the Norwegian-owned company winds its way through the long permitting process. In about two weeks, the company will file an application with the Maine Department of Environmental Protection for a pollution discharge elimination permit, the first of several local, state and federal permits to be obtained before construction can begin.

“Our production is dependant on having clean water,” Erik Heim, the founder of Nordic Aquafarms, said at the beginning of the presentation. “One of the reasons we ended up in this region was clean water. Clean, cold water is excellent for salmon.”

According to Nordic, the company will strive to keep that water clean as it is discharged into the bay. All fish production will take place indoors, using a recirculating aquaculture system, they have said, and groundwater from wells and ocean water from Penobscot Bay both will be used to produce the salmon.

Before being used in the aquaculture farm, ocean water will be treated and disinfected in a three-step process that culminates with ultraviolet light to make it “bio-secure” for the fish’s safety, Heim said.

Before water is released into the bay, it will be microfiltrated with a fine mesh and then dosed again by ultraviolet light. The combination is intended to neutralize potentially harmful bacteria and viruses in the discharge, he said.

Even filtered and cleaned, that discharge still would include chemicals and materials that are regulated by the state. Among those are total suspended solids, or undissolved particles in the water, which in high concentrations can reduce water quality and impair marine life.

The company will remove 99 percent of the suspended solids, but still would discharge a maximum amount of 185 kilograms per day, at a concentration of 6.33 milligrams per liter, which is a lower amount than the background levels of existing water in the bay.

The company also would discharge a maximum of 162 kilograms per day of biochemical oxygen demand, which represents the oxygen require to decompose the organic material in the water, and a maximum of 5.8 kilograms per day of phosphorus. That is the equivalent to the amount of natural phosphorus runoff from about 20 average lawns, according to Nordic Aquafarms.

If there is too much of the chemical element and nutrient in the water, it can cause algae to grow, which can harm water quality and decrease the oxygen that fish and other aquatic life need to survive. Nordic officials are telling the Department of Environmental Protection that the company will be able to reduce both phosphorus and biochemical oxygen demand by 99 percent, and that the amount that is left in the water will quickly be diluted to background water levels.

Finally, the company addressed nitrogen, a chemical element and nutrient that also can overstimulate the growth of aquatic plants and algae. Nordic would be able to reduce nitrogen by 85 percent, discharging a maximum of 673 kilograms per day into the bay at a concentration of 23 milligrams per liter.

The Environmental Protection Agency has set the maximum contaminant level of nitrogen at 10 milligrams per liter for safe drinking water. According to the company, dilution would reduce nitrogen level to the background level of the water, which is less than half a milligram per liter.

“The water being discharged is very, very clean,” said Nate Dill, a coastal engineer with Portland-based Ransom Consulting.

But that takeaway was sharply disputed by many in the audience who had questions — and, often, criticisms — for Nordic Aquafarms. Some people were concerned that the outflow pipe will only extend about one kilometer, or 0.62 miles, into the bay, and that fish could be fed soy or corn-based food.

Others spoke about the possibility that fish vaccines would eventually get into the bay, or about their worries that the nitrogen levels of the water will be too high, or that viruses could slip through the filters. Some felt that Nordic was basing its application on insufficient modeling, while others simply did not want anything else added to the bay.

“Any pollution is too much pollution,” one woman told company officials.

But some in the audience seemed glad, after months of uncertainty, to finally have something to scrutinize.

“Thank you for this presentation,” Mary Bigelow of Belfast, a former chief operator of a wastewater treatment plant in Vermont, said. “I’ve been hungry for numbers for months.”

Follow the Bangor Daily News on Facebook for the latest Maine news.