Wednesday, June 27, 2007

What the Long Island Sound Study Biennial Report Says and Does Not Say

The Long Island Sound Study’s biennial report on conditions in the Sound arrived in the mail the other day, at about the same time the Connecticut DEP’s summary and analysis of water quality in the Sound from last summer arrived.

I can summarize the DEP summary easily:

Hypoxia affected a larger area of the Sound last year than during the previous two summers, but it lasted for a shorter time than any summer since 2000. Here’s how Katie O’Brien-Clayton of the DEP put it:

In 2006, hypoxic conditions were estimated to have begun on 4 July and ended on 29 August, approximately 57 days. The peak event occurred in early August. The maximum area with bottom water DO less than 3.5 mg/L was 346 square miles. In 2006 the area less than 3.5 mg/L was larger than during the 2004 and 2005 seasons; however, the duration was the shortest since 2000.

She also included a bunch of graphs, from which I drew the following:

Over the last 16 years, the average number of square miles in which dissolved oxygen concentrations fell below 3.5 milligrams per liter was 188. Eight years were better than average, one was just about exactly average, and seven were worse than average. Three of those seven occurred in the last four years.

The average length of time that dissolved oxygen concentrations were below 3.5 milligrams per liter was 67 days. Eight of the last 16 years were worse than average, three were almost exactly average, and five were better than average. Five of the last six years were either worse than average or merely average.

Of course reaching an average of 188 square miles and 67 days is hardly the goal of the Long Island Sound cleanup.

Back in the mid 1990s, the folks working on the cleanup set a target for reducing nitrogen by 58.5 percent by 2014. When reached, that reduction would mean that the area in which dissolved oxygen fell below 3.5 would be reduced to 60 square miles, and the number of days in which dissolved oxygen fell below 3.5 would be reduced to three and a half.

Which brings me to what I consider an omission in the Long Island Sound Study’s biennial report: there’s no discussion at all about the actual condition of the Sound’s water. There’s a section about nitrogen reduction and a section about the amount of water quality monitoring done each year, but nowhere does it talk about whether the nitrogen reduction is resulting in an improvement in water quality. Why? Who knows. But maybe it's because the results are so inconclusive.

So there it is – in lieu of a discussion in the Long Island Sound Study’s biennial report of water quality conditions, you have my layman’s discussion of water quality conditions. Having said that, though, I should add that there’s lots of good stuff in the biennial report. Here, for example, is a long excerpt from an opening letter by Mark Tedesco, the director of the Long Island Sound Program:

What will it take to clean up Long Island Sound and restore the health of its natural resources? Simply put—creative partnerships and money. No major breakthroughs, just strategic investments of financial and human capital….

Our first challenge is to maintain, repair, and upgrade our wastewater and stormwater treatment infrastructure for existing development. Clean water does not come cheap….

The local need alone is in the billions of dollars. However, the benefits would also be enormous: more waters safe for swimming and recreation, more shellfish safe for human consumption, and healthier waters for aquatic life. The technical know-how exists. Funding is needed. …

Our second challenge is to ensure that new development is sustainable. New development simply cannot impose the same burden on the environment as past development if we expect a different environmental outcome for our streams and rivers, and for the Sound. We must develop and grow in ways that generate less polluted runoff, while protecting and restoring open space and natural habitats. The region has the human capital to accomplish this. The space to grow outward is quickly diminishing. We will need to grow up (literally and figuratively) and in. It is here where past and future investments in wastewater and transportation infrastructure can accommodate growth….

Not bad, considering that opening remarks or letters are usually a collection of platitudes. Give Mark credit for laying it on the line: we need to invest more money, and we need to stop sprawling all over the landscape and rebuild our cities (when I made the same point about how development should be concentrated in cities, in a talk to the Stamford Garden Club in April, the room erupted in a derisive guffaw).

Now here’s what the report says about nitrogen reduction:

The discharge of nitrogen from sewage treatment plants reached its peak in 1994. Since then, 39 of the region’s 104 sewage treatment plants have been upgraded to provide Biological Nutrient Removal (BNR) of nitrogen, resulting in about 40,645 fewer pounds of nitrogen per day. That’s enough nitrogen to fertilize 327,462 acres of turf for one year, an area nearly the size of the Bronx, Westchester County, and Stamford combined.

In 2005 and 2006, six nitrogen removal projects were completed at a cost of about $77 million. In addition, two interim plant upgrades were completed, and 13 other plants were undergoing construction. In spite of these actions, nitrogen loads increased by 6,000 pounds a day in 2005. New York City plants, which had been accomplishing moderate reductions of nitrogen, were “offline” during this period as a result of undergoing modernization. In addition, heavy rainstorms contributed to overcapacity problems in older plants that accept stormwater, diminishing the ability of these plants to treat nitrogen.

Both New York and Connecticut are implementing innovative programs to reduce nitrogen levels in phases by 2014. In Connecticut, communities that upgrade their plants receive nitrogen credits that are exchanged for cash through a state Nitrogen Credit Trading program. Communities that have delayed upgrades buy the credits at the exchange. The program takes into account that some plants can more cost-effectively remove nitrogen because of their size and design, or have a greater impact because of their proximity to the western Sound where hypoxia is more severe. New York’s plants are divided into five management zones. As long as each zone meets an aggregate nitrogen reduction target, all plants are in compliance. Every five years, the permitted aggregate nitrogen target is reduced for the zone, requiring more plant upgrades to go on-line.

Again, good stuff. The nitrogen reduction program seems to be moving along just fine, the increase in recent years is easily attributable to New York City (and probably understandable), and (based on what it says elsewhere in the report) the city is making progress on its own relaxed-schedule nitrogen removal program (that’s my phrase, based on the fact that the city agreed to meet its nitrogen reduction goal in 2017, three years after everyone else.

Here’s the link to the biennial report.



Blogger Sam said...

Is anyone operating a water quality model that produces and replicates resultant conditions such as hypoxia based on inputs such as nitrogen?

I think you hit the nail on the head when you indicated that all this monitoring is great, but unless you have some guidance to "roll back" pollutant inputs and estimate the results you really don't have much of a decision tool. In fact, one could make a case that with just monitoring, cause and effect would be completely unrelated, and you really can't predict anything.

Most lay people hate modelers and do not trust them. However, what one does is predict the severity and areal extent of the problem and then "train" or calibrate the model with real-world monitoring data. A mature and robust model would be invaluable as a "what-if" tool.

With such a model you could similate reduction scenarios or even turn off every wastewater treatment plant feeding into the LIS. I bet you would still see some hypoxia in the western LIS, but we need those kinds of maps to be able a guage our expectations.

Anyway, now you know the deep philosophical divide from monitoring and modeling camps.

Take hurricanes for example. Dr. Gray is the best monitoring guru of his kind in the world yet he misses stuff that the modelers said would happen. Last year, not a single one of the predicted hurricanes hit the US and the modelers knew that wind sheer and African dust would cut off all that tropical cyclone energy.

Too bad it is so hard make these virtual enemies work together!

4:42 PM  
Anonymous Anonymous said...

I am the communications coordinator for the Long Island Sound Study, and I wanted to comment on why we didn't report water quality conditions in the 2005-2006 Biennial Report. We made a decision to split our environmental reporting into two reports: the Biennial Report covers our management response to environmental conditions, while our Sound Health environmental indicators report will continue to report on the actual conditions of the Sound. The reporting is similar to the Chesapeake Bay program, which divides its report on the Health and Restoration Assessment of Chesapeake Bay into a Part One (Ecosystem Health) and a Part Two (Restoration Efforts. Our next Sound Health should be out by the middle of next year.
Robert Burg

2:22 PM  

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