NORWALK, Conn. – An environmental report released Tuesday gives Norwalk’s inner harbor an “F.”
“The 2020 Long Island Sound Report Card splits Norwalk Harbor into three segments with each receiving a grade representing environmental health. Inner Norwalk Harbor receives an F, Middle Norwalk Harbor receives a B-, and Outer Norwalk Harbor receives a B+. These grades are based on data collected as part of the Unified Water Study, a study fully funded by the EPA, administered by Save the Sound, and comprised of numerous water quality monitoring groups around the Sound,” Peter Linderoth, Save the Sound Director of Water Quality, said in a Wednesday statement.
The City received the “report card” Tuesday and is in the process of reviewing its conclusion, “in addition to potential contributing sources outside of the City (i.e. upriver),” Norwalk Chief of Operations and Public Works Anthony Robert Carr said in an email, promising “appropriate actions.”
Mayor’s Water Quality Committee Chairman Joe Schnierlein said he has many questions about the report card.
Save the Sound publishes its report card biennially, “to track and report on the ecological health of the Sound, including trend lines showing patterns over the past 12 years,” it states.
The inner Norwalk Harbor grade is the worst bay rating in Connecticut. Inner Eastchester Bay, inner Cold Spring and inner Manhasset Bay, all New York bays, were also given an “F.”
Dissolved oxygen concentrations were very low in the inner Norwalk harbor on multiple sampling dates, to the point of being defined as hypoxic by the EPA (U.S. Environmental Protection Agency) and DEEP (Connecticut Department of Energy and Environmental Protection), Linderoth wrote.
“This is harmful to marine life and can lead to die-offs. Macrophyte sampling also illustrates an abundance of seaweed in this segment of the harbor which is related to excess nitrogen entering the water,” he said.
“Inner Norwalk Harbor is listed by the state of Connecticut as impaired for multiple designated uses. It’s designation in the 2018 Integrated Water Quality Report (the state’s report to Congress) as impaired for marine life—with dissolved oxygen, nutrients, and total nitrogen listed as causes—further supports the F grade assigned by the Long Island Sound Report Card. The current DRAFT 2020 IWQR includes these impairments and causes too.
“Inner Norwalk Harbor is in need of restoration actions. It is currently not meeting CT water quality requirements and subsequently is listed as an impaired waterbody in CT and with the EPA as required under the Clean Water Act. Save the Sound urges Norwalk residents and municipal leaders to take actions to restore Inner Norwalk Harbor. Reducing impervious surfaces (roads, parking lots, roofs), capturing and infiltrating stormwater with green infrastructure, fertilizer application reduction in the lands draining to the harbor, removal of a combined sewer overflow and the unacceptable number of sanitary sewer overflows that enter the water, upgrades/repairs to aging sanitary sewer infrastructure, and other measures to reduce nitrogen entering the waterway could all yield positive results.”
“Within recent decades, water quality within the Norwalk Harbor has experienced significant improvements,” Carr wrote. “Like all concerns raised with the City, we take these findings very seriously. We will continue to evaluate the limited contents of the Save the Sound Annual Report Card 2020, and will take appropriate actions as necessary.”
“I am waiting to get feedback from the organizations that do the sampling, including Save the Sound,” Schnierlein wrote. “However, there are several questions that I have concerns about.”
- “a) First, the data used was from 2019, not 2020 so the report should have been labeled the 2019 report. And, the sampling is not done all year long.
- “b) We have known for over 40 years that when the water temperature rises above 70 deg. F., that dissolved oxygen levels drop especially in the upper harbor. If there is not enough rain and therefore runoff, the upper harbor becomes hypoxic, and then anoxic. That does not mean that there aren’t fish in that area, however. The cormorants and osprey can be seen working the waters in that area collecting dinner for themselves and their offspring. These fish are getting their dissolved oxygen from the upper surface where there can be oxygen at the air/water interface. It is by no means dead as an “F” would indicate. Indeed, fishermen that have been in Norwalk for a long time will tell you that a large school of menhaden can suck up all of the oxygen in a harbor and kill themselves – some may remember when this happened before one of the early Oyster festivals and the harbor had to be cleared of dead and rotting fish before the festival.
- “c) Chlorophyl a does not measure all of the phytoplankton in the water. It only measure the phytoplankton that have chlorophyll a, and as some phytoplankton have more a than others, it is only an estimate. There are other types of photosynthetic pigments found in phytoplankton, and, if plankton samples were done, one could see that there are seasonal changes.
- “d) Turbidity tests should not be an “A”, “B” or “C” through most of the summer. Shell-fishermen pray for more turbid water as it is more food for their shellfish, making them gain weight and grow faster. Most people who stick their toes in the water during the summer can rarely see them if they are in water up to their knees. If that sampling was done using a secchi disk (old school), then the sampling was from the surface. If a turbidity meter was used, then it should indicate surface, mid water and bottom readings. Zooplankton and phytoplankton go through vertical migration that is triggered primarily by sunlight. This movement would affect turbidity readings. Other factors that affect turbidity are algae blooms, storms stirring up sediments, cloudiness, boat traffic in shallow water, shellfishing or dredging. It usually isn’t until December that the water clears up and becomes less turbid or, large schools of menhaden (bunker) hit an area and graze on the plankton.
- “e) Under oxygen saturation, they make the statement that “healthy water should have oxygen levels in equilibrium with the air, termed 100% saturation. Water quality problems are indicated when oxygen is consistently higher or lower than 100% saturation.” Fish that typically live on the bottom, such as sea robins, flounder, black fish and many crab species are adapted to living in lower levels of oxygen. Fish on the surface are adapted to higher levels of oxygen. And fish that live near a rocky shore or a shore with a lot of wave action are adapted to higher levels of oxygen. Summer water is typically warmer, and holds much less oxygen than winter water. And, depth is a factor for oxygen saturation with deeper water usually holding less oxygen. “f) Nitrogen sampling is not indicated in the report, but they claim it is a problem.
- “g) At no time did Save the Sound report any of their perceived issues to me or the city, which could help us address the issue at that time instead of having it linger.
- “h) Testing is not only done by Save the Sound, but also by the Sewage treatment plant, the Norwalk Health Dept, the Dept. of Aquaculture, Earth Place, and Norm Bloom shellfish. The later let the proper people know immediately if there is an issue.
- “i) if there is a claim that runoff and pollution are a factor in this, then there should be evidence of this. But, it is not reported. No results from nitrogen tests, PFAS or PFOS tests, lead, mercury, PCB tests, etc.”