HARWICH — While funding and technical details relating to the design alterations of the Harwich Conservation Trust's Robert F. Smith Cold Brook Preserve are still being discussed, town officials, consultants, state and trust representatives are confident they are getting close to a final plan.
“We're actually getting close and I can't think of a more exciting project to address the nitrogen issue,” said David Young of DCM Smith, Inc., the town's wastewater consultants. “It's getting close to a good ecological conservation project.”
HCT is seeking to develop an ecological restoration plan for the 66-acre former Bank Street cranberry bogs it now owns while the town wants to work with the trust to shape the design so that it will remove nitrogen from the groundwater to help satisfy the town's comprehensive wastewater management plan.
The HCT received a $40,000 grant from the Massachusetts Environmental Trust to hire Inter-Fluve, Inc., a Cambridge based engineering firm that specializes in river and wetland restoration, and the trust has been working closely with the Division of Ecological Restoration within the Massachusetts Department of Fish and Game and the U.S. Fish and Wildlife Service in shaping a plan to restore the former bogs.
The trust also received initial notice of an estimated $1.5 million grant from the Cape Cod Conservation District for the project, part of a $10 million U.S. Department of Agriculture Natural Resources Conservation Service appropriation for water resources restoration projects. But Harwich Conservation Trust Executive Director Michael Lach said there is no guarantee the trust will have access to the funds. The initial intent, he said, was to use the money for restoration construction and provided until November 2019 to complete the work.
“We determined our time line wouldn't match up,” Lach said, adding the project is still in the design phase and permitting could take a year or more. “We've had a handful of conversations with the town, Division of Ecological Restoration and Division of Marine Fisheries. The Natural Resources Conservation Services has yet to decide if we can use these funds for gathering information. We're not sure whether we'll get them or not.”
The goals of the ecological restoration project include removal of degraded water control structures such as old flumes in Cold Brook, restoring tidal flow to the southern section of the property and improving fish and eel passage to the headwater pond.
In its comprehensive wastewater management plan, the town identified the former cranberry bogs and Cold Brook stream system as a location where a natural attenuation system utilizing ponds can be established to reduce nitrogen generated from septic systems within the Saquatucket Watershed.
The goal is to reduce nitrogen in the saltwater because it acts as a fertilizer feeding algae blooms and depriving the marine habitat of oxygen, which degrades the health of the embayments. It is estimated more than 70 percent of the nitrogen infiltrating saltwater comes from septic systems. The Massachusetts Estuary Project determined that 100 percent of the nitrogen from Wychmere Watershed and between 70 to 90 percent from the other four watersheds in town needs to be removed, including 58 percent from the Saquatucket Watershed.
The town has approved $2 million for the Cold Brook project because it will reduce the need for sewer infrastructure to remove nitrogen and save the town money. Town Administrator Christopher Clark told selectmen Monday night the Cold Brook project will reduce the need to sewer 240 homes, saving $6 million and with already-approved funding providing a net benefit to the town of $4 million.
The town has been working with HCT to develop a system that will serve duel goals. On Friday, more than a dozen state, local and HCT representatives and consultants met in town hall to discuss progress on the design. One of the major points of discussion was the amount of ponding to be located in the preserve. The ponds provide a period of residence for nitrogen, allowing its removal through conversion to a gas and uptake by plant life.
“We have concepts we'd like to see for nitrogen reduction,” Town Administrator Christopher Clark said.
Young said the initial desire was for a dozen acres of the site to be converted to ponds. The ponds have to be located at the upper east side of the property, where 60 percent of the groundwater flows into the site from the more heavily populated section of the watershed. He said the town is now seeking 4.9 acres of ponds but is looking for greater depth.
“Area and depth create residence,” Young said of the process. The recommendation by the Division of Ecological Restoration to HCT was for 2.6 acres of ponds.
They are only two acres apart, said HCT trustee Colin Leonard, adding they might consider 3.9 acres with a deeper retention basin, which would provide better water quality and less mosquitoes.
Brian Howes of the School of Marine Science and Technology at UMASS Dartmouth, which conducted the Massachusetts Estuary Project that set total daily maximum load limits of nitrogen for watersheds, said two acres could make a functional difference and could have a big impact on the nitrogen removal project.
The group also discussed the permitting process facing the project and the need to define which funding buckets work on the various segments of the project.
“I think we're getting closer to a decision on portion of the design process,” HCT Executive Director Michael Lach said. “We'll continue the conversations with the Division of Ecological Restoration, U.S. Fish and Wildlife Service, town and its consultants.
“I don't see this as a standoff or a hard line. The conversation is continuing. The Division of Ecological Restoration and U. S. Fish and Wildlife are examining it so we'll be able to reply soon. Hopefully we can reach a compromise for the ecological restoration area,” he said.
“Harwich Conservation Trust's focus is continuing on vistas and natural settings and as much biodiversity as possible,” Clark said. “I think [nitrogen] mitigation and biodiversity can go hand-and-hand. It's taking science that has been proven in components and putting it into one big piece.”
The group has agreed to meet on a more frequent schedule, including one more meeting before the May 7 annual town meeting.