By Anna Meyer
In the Missisquoi and St. Albans bays of Lake Champlain, dense blooms of potentially harmful blue-green algae appear in late summer and early fall.
On Cape Cod, the once-sandy floors of inlets are coated with thick mats of algae.
Each summer in Long Island Sound, hundreds of square miles of bottom waters are so oxygen-poor that they are unhealthy for, or uninhabitable by, fish and other aquatic animals.
The cause of all of these impairments is the same: excessive algae growth fed by excessive nutrient inputs. The nutrients come from nonpoint sources, which are diffuse and often invisible to the naked eye, as well as point sources such as effluent from wastewater treatment plants.
In Lake Champlain, as in many freshwater systems, phosphorus is the main nutrient that stimulates blooms. Runoff from agricultural land, especially cropland, is recently the source of about 40 percent of phosphorus to the lake from Vermont.
Nitrogen is the main nutrient of concern in Long Island Sound and the coves, or embayments, of Cape Cod. Leachate from septic systems into groundwater is the largest source of nitrogen to the embayments on the Cape. The largest sources of nitrogen to Long Island Sound from the five-state watershed are effluent from wastewater treatment plants and runoff from forests and urban areas.
In all three places, states are tackling nutrient pollution head on. In the Long Island Sound watershed, Connecticut and New York have made a concerted, successful effort to increase the nutrient removal capacity of wastewater treatment plants in the watershed. New York completed a series of wastewater-plant upgrades just this spring.
When it comes to nonpoint source pollution, these areas provide examples of states stepping up to require best-management practices where the federal Clean Water Act does not.
In Vermont, for example, new state regulations require many farms to minimize runoff. The U.S. Clean Water Act requires point-source permits for some types of agricultural nonpoint source pollutants, such as runoff from concentrated animal feeding operations, but the state rules apply to a much broader group of farms.
In Cape Cod, creation of a new type of state-issued permit has catalyzed a flurry of collaborative nutrient-management planning among towns. The watershed permits get around logistical and financial challenges that had previously hindered towns on the peninsula from improving embayments degraded by nutrients.
In the Long Island Sound watershed, Connecticut’s new general permit for stormwater sewer systems is stricter than previous iterations and it covers more of the state.
Sidebar: “A Glut of Nutrients” describes how nutrient pollution can feed blooms of algae and phytoplankton with cataclysmic effects for aquatic life.
More than ninety percent of the phosphorus entering Lake Champlain from Vermont comes from nonpoint sources, and nearly half of that comes from agricultural lands. The phosphorus feeds blooms of algae that are increasingly in the public eye.
New and revised required agricultural practices, which became effective in December of 2016, are aimed at reducing runoff of soil and manure from croplands and pastures.
The regulations require such practices as maintaining vegetated buffer zones near surface waters and fencing livestock out of streams that have eroded banks. They govern the proximity of manure spreading to drinking-water supplies.
Kari Dolan of the Vermont Department of Environmental Conservation’s Watershed Management Division says that the state needed to ensure that the new regulations for farms of all sizes would be feasible. “We want to support this sector as best we can,” Dolan says.
The required agricultural practices are among several new and revised regulations that support the implementation of revised phosphorus targets (total maximum daily loads or TMDLs) for the twelve segments of Lake Champlain influenced by inputs from Vermont.
Related regulations address other nonpoint sources, including runoff from paved roads and unpaved roads, and erosion of forest lands and unstable stream channels.
In Vermont, only nine municipalities have separate storm sewer systems. That leaves more than two hundred towns with stormwater infrastructure that isn’t managed by a permit. Later this year, however, stormwater practices in all of those communities will be covered by a statewide municipal roads general permit.
“Practices for pollution control are good for resiliency,” Dolan says. Such practices include properly sizing and stabilizing culverts (tunnels for streams to flow under roads), and building drainage ditches to be U-shaped instead of V-shaped. The better shape slows the flow of water to maximize infiltration and minimize conveyance.
Another general permit due out later this year will require stormwater controls in all new and existing properties with at least three acres of impervious surface.
As of December 28, 2016, Vermont’s Department of Transportation is subject to a new general permit for all state-owned roads. The permit allows the state to prioritize stormwater controls in areas of concern, such as roads where runoff flows directly into a stream Previously, the Department waited until those same roads were in need of maintenance or widening.
In October of 2016, the state’s Department of Forests, Parks, and Recreation improved its acceptable logging practices for maintaining water quality. Although phosphorus runoff rates per acre from forestland are very low compared to rates from other land uses, more than 70 percent of the Lake Champlain basin is forested.
Between 2001 and 2010, the average annual phosphorus input to Lake Champlain from forested land in Vermont was 101 metric tons, or 16 percent of the phosphorus load from the state.
The new practices aim to reduce sediment pollution from erosion of bare land exposed by harvesting.
Lake-shore property owners in Vermont have many reasons to support the state’s pollution control efforts. Cyanobacteria blooms, which can turn large areas murky or opaque, can release toxins that are harmful to animals and people. Furthermore, the blooms take a measurable toll on property values.
According to a 2015 study sponsored by the University of Vermont and the Lake Champlain Basin Program, a one-meter decrease in water clarity leads to an average 37-percent depreciation in the selling price of seasonal homes in Vermont towns near Lake Champlain. The loss for year-round single-family homes is 3 percent.
The study also estimated that every one-meter decrease in water clarity during the months of July and August leads to a $12.6 million drop in lake-related tourism.
The Connecticut Department of Energy and Environmental Protection is addressing urban stormwater as part of a decades-long effort to contend with nitrogen loading to Long Island Sound.
Scientists have monitored dissolved oxygen levels throughout the Sound since 1987. Data show that oxygen depletion, or hypoxia, in the bottom waters of the Sound is common during the later summer months.
The maximum area of hypoxic conditions, under which oxygen-breathing aquatic organisms become physically stressed, averaged 183 square miles from 1987 to 2016. In rare instances hypoxic conditions have resulted in visible fish kills.
In recent years, Connecticut has redoubled its efforts to minimize nonpoint pollution from stormwater. A new general permit for municipal separate storm sewer systems (MS4s) went into effect on July 1, 2017.
The previous version of the MS4 general permit applied to 113 municipalities. The new one includes 8 additional towns as well as state and federal institutions that operate stormwater systems. These include prisons, colleges, military facilities, and hospitals.
New elements in the 2017 permit include a requirement that low-impact-development measures be used in new construction. There are also new requirements for MS4s that discharge to impaired waters.
The new general permit asks a lot of public works managers. Consequently, the state has retained the University of Connecticut’s Center for Land Use Education and Research to provide technical assistance to municipalities and institutions.
On Long Island, the Long Island Nitrogen Action Plan (LINAP) is examining both regulatory and non-regulatory measures to manage use of residential and commercial fertilizer. Other LINAP efforts include detailed groundwater modeling and also homeowner grant programs for the replacement of conventional septic systems and cesspools with cleaner onsite wastewater treatment systems.
Andrew Gottlieb, the executive director of the Association to Preserve Cape Cod, remembers when the Cape’s inlets were sandy under foot.
But today they’re mucky. Thick mats of decomposing algae are common. Sometimes they float to the surface, bringing an unpleasant smell. There have been occasional fish kills related to depleted oxygen.
Cape Cod’s shoreline has fifty-three discrete coves, or embayments. Twenty-two are highly threatened because of nitrogen enrichment, and another eleven are moderately threatened.
The problem is deceptively simple. Around 80 percent of the controllable nitrogen load is from onsite septic systems, which are not designed to remove nitrogen from wastewater. Why not just sewer the whole peninsula, which is just ten miles wide at its widest point?
Collection and treatment systems are costly and would need to be designed for peak flows. These occur just four weeks a year, during the height of the summer tourism. Consequently the Cape’s year-round population would shoulder a significant share of the $6 to $8 billion price tag.
To complicate matters, thirty-two of the embayments are influenced by pollution from two or more towns, creating a disincentive for towns to invest in their own sewer systems.
Conventional wastewater collection and treatment, however, is far from the only option, and, as of 2015, there is jurisdictional framework for Cape Cod’s towns to work together on pollution management in a shared watershed.
These watershed permits will allow towns individually or as groups to reduce nitrogen pollution through a combination of traditional and nontraditional strategies. Technology options include standard septic systems and conventional sewers, as well as vegetated bioretention filters, composting toilets, and permeable reactive barriers to intercept groundwater and remove nitrogen.
The new type of permit was introduced in the Cape Cod Area Wide Water Quality Management Plan Update, known as the 208 Plan after Section 208 of the U.S. Clean Water Act. EPA Region 1 approved the plan update in 2015.
The Cape Cod Commission, a regional planning agency with regulatory powers by statute, developed the plan with funds from the Massachusetts Department of Environmental Protection as part of a settlement from a 2010 lawsuit brought by the Conservation Law Foundation.
The Massachusetts DEP, EPA Region 1, the Cape Cod Commission, and other partners are still developing the new permit process. Generally, each town will maintain its regulatory autonomy and have responsibility for a share of the nitrogen load to a watershed, but towns will be able to adopt intermunicipal agreements.
The 208 Plan has unleashed active cooperation among the peninsula’s communities. As of the summer of 2017, each one of Cape Cod’s fifteen towns is involved in discussing or planning for at least one of the shared watersheds.
Gottlieb lauds the 208 Plan as a means of addressing a problem that residents of Cape Cod already knew well. “It’s the combination of various management approaches that bring the cost down to make it financially feasible for communities,” he said.
Ron Poltak, NEIWPCC’s recently retired former executive director, has watched the science and technology of nutrient pollution from nonpoint sources evolve while federal policies have continued to make management largely voluntary and optional.
“We’re going to continue to have waterbodies that don’t meet water quality standards because of nonpoint source pollution. We’re going to have to be able to mandate the best management practices applied,” Poltak said, “It’s simple, just mandate.”
The Clean Water Act’s mandatory protections on nonpoint source pollution are limited, but Northeast states are stepping up to fill in the gaps.
Anna Meyer is an Environmental Analyst at NEIWPCC.
This story is available as a reprint, part of a series from NEIWPCC. It was originally published in the March, 2017, issue of Interstate Waters.