Harwich Water Quality Task Force Maintaining and restoring the Quality of Harwich Ponds and Harbors Harwich, Massachusetts Return to Harbors

INTERIM REPORT
FOR  2003
December, 2004

Prepared by
Water Quality Management Task Force
Town of Harwich

 Inquires: Frank Sampson , Chairman WQTF, 109 Riverside Dr. W. Harwich. 432-4279; sampscape@capecod.net

Table of Contents
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Acknowledgments
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 The success of the Harwich Coastal Water Quality Monitoring Program rests with the dedication of  manager ( trainer and cheerleader!) Heinz Proft and its volunteers who spend many hours training, collecting water quality samples, and transporting samples to the laboratory for analysis.  THANKS TO ALL OF YOU!

We also want to extend a special thanks to the Pleasant Bay Monitoring Program for the wonderful sharing of experience and information, especially Bob Duncanson, PhD, director of the Chatham Dept. of Health and Environment. We were given a  real jump-start by that program.

And last but not least to Tom Leach, Director of  the DNR, for his continuing support of the program.

This report was prepared by Larry Ballantine, Phd. and Frank Sampson

 
 Introduction
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            This report summarizes water quality data collected by the Town of Harwich Coastal Water Quality Monitoring Program during 2001, 2002 and 2003. Bacterial data includes 2004 This program was initiated in 2001 by the Harwich Water Quality Task Force (WQTF) and is managed through Harwich’s Dept of Natural Resources (DNR) by Heinz Proft, Assist. Harbor Master, under the direction of the Town of Harwich Water Quality Task Force ’s Sampling subcommittee. Members of the subcommittee include Paula Champagne, Health Director, Heinz Proft, Danette Gonsalves (WQTF) and Frank Sampson (CH. WQTF).

            This report is an interim report, because multiple consecutive years worth of consistent data are necessary to determine trends and begin to draw conclusions about water quality .  While the data summarized in this report may be indicative of water quality throughout the estuaries of Harwich, it is too soon to tell conclusively.  However, the report provides an important baseline against which future data will be analyzed.  Given the high degree of public interest in water quality conditions, the program plans on providing yearly interim reports.  A more comprehensive report will be published when additional years of data have been collected and analyzed. A companion report on the fresh water-sampling program is also available.

The report contains the following sections:

         A brief summary of overall findings, with emphasis on total nitrogen levels, phytoplankton levels, and the Eutrophication Index calculated for each embayment.

 Summary sampling data for each monitoring station, along with figures depicting levels of dissolved oxygen.

 A summary of the bacterial sampling program, along with an analysis of the results to date

background
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       Estuaries (embayments), places where coastal waters and fresh waters meet and mix, are extremely sensitive to the effects of nitrogen. It is not the nutrients themselves that cause problems, but the increased plant growth that results. Certain algae, both macro-algae (“seaweeds”) and phytoplankton, become so abundant that they shade the bottom and decrease the light available to submerged aquatic plants such as eelgrass. As the plants die and decay they use up oxygen and the plant remains settle to the bottom. This excessive production and decay can reduce the amount of oxygen in the water column and can ultimately lead to hypoxic (low oxygen) or anoxic (no oxygen) conditions. Even short periods of low oxygen can cause serious damage to bottom dwelling organisms and eventually lead to further losses of plant and animal species.
        Nitrogen travels to an estuary through the groundwater or over the land as run-off. It can take years for nitrogen traveling via groundwater to reach a receiving water body. On Cape Cod groundwater travels an average of one foot per day. Thus, even if new development stopped today and nitrogen from existing development was severely limited, nitrogen would continue to arrive at the estuaries over a long period of time.
        These same estuaries are our shellfish resources and have been plagued by closures for many years due to elevated levels of bacterial contamination from a multitude of sources, including storm water runoff, domestic and wild animal population and heavy near shore residential development.
        The water quality sampling program was initiated to allow the Town to gather data over a number of years to come to a better understanding of existing water quality in a quantitative way and to serve as a foundation for evaluating means to maintain or restore desired water quality in each of the Town’s estuaries. The WQTF has a long-range objective of developing a Town-wide management plan for all of Harwich’s critical water resources.
        Program funding is provided by the Town and through past grants from the state Executive Office of Environmental Affairs Citizen Monitoring grant program.

 The primary program objectives are:

 ·   To provide background data on current water quality conditions;
             ·   To provide data for comparison to applicable water quality standards, guidelines, goals, indices, etc.
                    as available;
             ·   To provide town-wide data allowing the comparison of the various embayments to each other and to                       watershed conditions, thereby allowing targeting and prioritization of remediation activities and funding;
             ·     To provide the data necessary for water quality modeling as part of the Department of Environmental                        Protection’s Massachusetts Estuaries Project (MEP);
             ·     To provide data to target more intensive study efforts to those locations identified as degraded based                        on the monitoring effort; and
             ·     To provide long-term data enabling the determination of trends in various water quality parameters,                        thus providing a measure of the success (or lack thereof) of remediation activities.

        The MEP is designed to work with communities using actual water quality, hydrodynamic, and land-use data in a model to determine critical nitrogen loads in coastal embayments. The modeling is intended to lead communities to a clear definition of critical nitrogen loads and development of appropriate nitrogen management strategie

Methodology
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 The program monitors water quality at 11 stations located the Nantucket Sound estuarine waters of Harwich (Table 1). Two other stations on Pleasant Bay (Round Cove & Muddy Creek) are monitored by the Pleasant Bay citizen Water Quality Monitoring Program. A separate report covers the data collected in that program. The Pleasant Bay program samples the control in Nantucket Sound also.

Samples were collected in June, July, August, and September. Samples were collected at two depths (0.5m below the surface and 0.5m above the bottom) for two (2) stations and at mid depth for nine (9) shallow stations.  Once collected, and filtered as appropriate, water samples were transported to the SMAST Coastal Systems Laboratory for nutrient analysis. Bacterial samples were collected at the nutrient sampling stations and seven (7) other critical locations and taken to the Barnstable County Lab.

In 2002 storm water sample were collected at critical discharges from Rte 28 and town property draining to Allen’s harbor

Table 1 Harwich Sampling Locations

*done by Pleasant Bay program; **added in 2002
To date more than 40 volunteers have been recruited and trained to monitor field conditions and collect water quality samples from both salt and fresh water systems(15 ponds)

Parameters
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 Volunteer teams are equipped to conduct field measurements for total depth, Secchi depth (measure of water transparency), surface salinity, temperature, dissolved oxygen, weather, wind speed and direction, and sea state. In addition, water samples are collected for laboratory analysis of nitrate and nitrite, ammonium, orthophosphate, dissolved organic nitrogen, particulate organic nitrogen, particulate organic carbon, phytoplankton pigments, and salinity.

 Bacterial analysis is for fecal coliform, a surrogate indicator of organisms found in the intestines of warm-blooded animals and humans.

Many of the parameters have been chosen for their direct measure of the environmental condition of estuarine and coastal waters. Other parameters (such as salinity and weather conditions) are useful in the interpretation and understanding of the chemical analysis results. Many of the parameters being measured are employed in the calculation of the Eutrophication Index (see below). The parameters being measured are briefly described below.

 Salinity.  Salinity is a measure of the amount of dissolved salts in a given volume of water and is generally expressed in parts per thousand (ppt). Salinity ranges from approximately 35 ppt in the open ocean to 0 ppt in freshwater systems. Salinity varies throughout the tidal cycle and with changes in freshwater inputs through groundwater and surface discharges. Salinity plays a role in determining oxygen levels as lower salinity water can hold more oxygen than higher salinity water. Salinity can also affect oxygen levels through the process of stratification (lack of vertical mixing) whereby more dense, higher salinity water is overriding by lighter, less dense freshwater. This stratification prevents mixing and diffusion of oxygen from the atmosphere to the deeper waters.

Temperature.  Temperature is one of the most important measurements due to its role in controlling, along with salinity, the amount of dissolved oxygen water can hold. All other factors being equal warmer waters will generally hold less oxygen than colder waters. Warmer waters also tend to have higher levels of biological activity that use up oxygen more rapidly. Differences between surface and bottom temperatures also provide an indication of the extent of stratification in the water column.

Dissolved Oxygen (DO).  Dissolved oxygen is a measure of the amount of oxygen molecules dissolved per given volume of water and is generally expressed as milligrams per liter, mg/L (equal to parts per million, ppm). DO levels can also be reported as percent saturation that takes into account temperature and salinity to report the measured DO as a percentage of what the water could theoretically contain. Sufficient levels of DO are required for the growth and survival of most aquatic organisms. Lower DO levels can result naturally from the effects of temperature and salinity as discussed above. However, more frequently, low DO levels reflect increased biological activity (respiration) and/or the effects of compounds using oxygen during decay (“oxygen demand”). Such demand can originate from decay of natural organic matter or from the effects of introducing various pollutants, including nutrients. Replenishment of oxygen generally occurs via two mechanisms, exchange with the atmosphere and photosynthesis. As a result, oxygen levels are generally lowest in the early morning and are further impaired on calm, cloudy days.

Most aquatic organisms function well when DO levels are generally above 5 mg/L. Many organisms, especially those that are non-motile (i.e. shellfish) will begin to experience stress with DO levels between 3-5 mg/L. Levels between 3 and 0.5 mg/L (“hypoxia”) will result in species leaving the area or dying if non-motile. Levels below 0.5 mg/L (”anoxia”) will cause the death of any organism that requires oxygen. In addition to the level of DO, the extent of low DO conditions is also important. Many species can tolerate short periods of hypoxic conditions without ill effect, however, if these periods are prolonged or frequent then effects become more severe.

Secchi Depth.  Secchi depth is a measure of the clarity (transparency) and light penetrating ability of the water and is affected by the amount of suspended material in the water.  Suspended material may be biological (phytoplankton and zooplankton) or non-biological (silt/sediment). Low transparency waters will adversely impact submerged aquatic vegetation (i.e. eelgrass) by reducing the amount of light available for growth and photosynthesis. Transparency can be affected by natural mechanisms such as storm events that re-suspend bottom sediments and increase runoff from terrestrial sources. Transparency in aquatic systems is frequently affected by the growth of phytoplankton in response to available nutrients. Phytoplankton “blooms”, the result of over-stimulation of the system by excessive nutrients, can reduce transparency to near zero with significant impacts to aquatic organisms and vegetation. Secchi depth can range from less than 1 meter in highly nutrient enriched embayments to greater than 4 meters in offshore waters.

Phytoplankton Pigments.  Measuring plant pigments (chlorophyll a and its breakdown product pheophytin a) provides an estimate of the algal biomass, primarily phytoplankton (small, mainly microscopic plants and algae suspended in the water column), present in the water. High concentrations are usually found in water bodies with elevated nutrient inputs. Algal populations will vary throughout the year depending on temperature, light levels, and nutrient availability. The National Estuarine Eutrophication Assessment² found chlorophyll a levels below 5 micrograms per liter, ug/L (equal to parts per billion, ppb) to be associated with low ecological impact.

Nutrients.  Biological activity, whether terrestrial or aquatic, is driven by the availability of nutrients along with light and temperature. In marine systems nitrogen is generally the “limiting” nutrient (i.e. is naturally in shortest supply) for growth, while phosphorus is generally limiting in freshwater systems. Excessive nutrient loading (“eutrophication”) is driven primarily by anthropogenic sources (wastewater, fertilizer, runoff, atmospheric deposition, etc.) and results in greater and more frequent growth of aquatic plants (principally macroalgae and phytoplankton). This increased growth reduces water transparency and dissolved oxygen, thereby changing the nature and composition of existing plant and animal communities.

Dissolved Inorganic Nitrogen (DIN).  The three principal forms of inorganic nitrogen are ammonium, nitrite, and nitrate. These are the forms via which most of the nitrogen enters coastal waters from wastewater, fertilizer, runoff, and atmospheric deposition. These biologically active forms are usually present in low levels as plants rapidly take them up. High measured levels are usually an indication that the system is severely overloaded (eutrophic).

Dissolved Organic Nitrogen (DON).   Organic nitrogen results from the incorporation of inorganic nitrogen into living tissue. DON is a mixture of more complex organic nitrogen containing compounds released by living organisms and decaying matter. DON levels are generally higher in eutrophic waters reflecting the higher amounts of living material.

Particulate Organic Nitrogen (PON).   PON is inorganic nitrogen that has been incorporated into tissue, both living and dead, primarily phytoplankton, macroalgae and larger aquatic organisms. Eutrophic waters will generally have higher levels of PON than less nutrient enriched waters.

Particulate Organic Carbon (POC). POC is another measure of the quantity of tissue, living and dead, present in the water column. Carbon is also essential for the formation of living tissue. 

Orthophosphate (PO4).  Although phosphate is generally not considered a limiting nutrient in marine systems determining its levels can provide an indication of the influence of freshwater inputs to the systems.

Total Nitrogen (TN).  Is the sum of organic (DON, PON) and inorganic (DIN) nitrogen, and will be high in an estuary that is eutrophic.  In many estuaries in southeastern Mass. TN levels above approximately 0.35 mg/L have been associated with negative ecological impacts, such as loss of eelgrass. However, an appropriate TN level must be determined for each embayment individually due to differences in flushing rates, embayment volume, watershed size, watershed nitrogen loading, etc.

Fecal Coliform . Is a surrogate organism used to indicate the probable presence of waterborne pathogens from warm blood creatures (human or animal) and the potential risk to public health. The regulatory threshold for shell fishing is 14 colony-forming unit per 100 milliliter (CFU per 100 ml), 200 for swimming and 1,000 for human contact of any kind.

Eutrophication Index
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The Eutrophication Index, developed by the Buzzards Bay Project³, is a method to synthesize a vast amount of data into a more easily understood format. The Index is widely accepted as a tool for assessing the impact of excessive nutrients from surrounding land uses and for monitoring the general condition of coastal water quality.  The Buzzards Bay Baywatcher’s program has used the index since 1992.  The Index uses the average summer values for oxygen saturation (lowest 20%), water transparency (measured by Secchi depth), phytoplankton pigment, dissolved inorganic nitrogen, and total organic nitrogen to develop a relative rating for each sub-embayment. The ratings are then related to water quality conditions through the following scale.

 Water Quality Condition Based on Eutrophication Index

Quality Control
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 Quality control procedures for the program are detailed in the Town of Harwich Water Quality Monitoring Program Quality Assurance Project Plan (QAPP) which was prepared by SMAST. The QAPP provides specifications for sampling, handling and transport of samples, replicate sampling to evaluate the statistical reliability of samples, and instrument testing, inspection and maintenance

Summary of Findings
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A summary of data for 2001, 2002 and 2003 (WQTF web site only) is contained in appendix A

Total Nitrogen

 Figure 1 presents the Total Nitrogen (TN) results for the Nantucket Sound embayments. With few exceptions all stations significantly exceed the average “background” level as measured at the Nantucket Sound control station. Based on 3 years of data (1999-2001), the “background” TN concentration in Nantucket Sound averages 0.314 mg/L

The exceptions are Hulse Point at the entrance to Allen Harbor and Wychmere outer Harbor.  These stations are expected to be better than the main harbors and more reflective of Nantucket sound. They were added this year to assist in the modeling effort after consultation with SMAST.

The data for Herring River at the herring run (West Reservoir) is entirely fresh water and Lothrop Rd is mostly fresh water, both are inputs to the Herring River system.

Year to year variations are expected due to a variety of reasons including different rainfall/groundwater flows and inconsistencies associated with a large field data collection program. This is why several years of data are needed to reach meaningful conclusions.

Phytoplankton

             Figure 2 present the Phytoplankton pigment results.  Again with the exception of Hulse Point and Wychmere outer Harbor, phytoplankton concentrations for most stations greatly exceed 5 ug/L. The National Estuarine Survey found levels below 5 ug/L to be associated with low ecological impacts.

The levels for west Reservoir are indicative of a shallow fresh water system, which receives nutrients, particularly phosphorous, from the entire Herring River watershed of over 10,000 acres

   Eutrophication Index

 Figure 3 present the calculated Eutrophication Index for each sampling station except the Herring run and Lothrop Rd , which as discussed earlier represent mostly fresh water systems.

 As can be seen all stations show an impact from nitrogen originating in their respective watersheds. The three harbors in Harwich Port are clearly impacted which is not surprising considering that the watersheds are for the most part fully developed, particularly Allen Harbor. Once again Hulse point and the outer Wychmere Harbor are closer to the Nantucket Sound background.

The data for Herring River must be interpreted in the light of previous studies on Herring River 5,6 and elsewhere that show that much of the observed nitrogen may come from natural wetland systems and in fact along with the many fresh water ponds upstream are capable of removing significant amounts of the nitrogen load from the watershed. Much further work is necessary to quantify this effect including the modeling under the MEP

Dissolved Oxygen

 Appendix B contains individual figures for each station showing the Dissolved Oxygen (DO) results. Each figure contains 2 graphs; the first shows dissolved oxygen in mg/L relative to the State Surface Water Quality Standard (314 CMR 4.00) for “SA” waters. Class SA waters are those marine waters:

            “…designated as an excellent habitat for fish, other aquatic life and wildlife and for primary and secondary contact recreation. In approved areas they shall be suitable for shellfish harvesting without depuration. These water shall have excellent aesthetic value”.  

DO levels in Class SA waters “Shall not be less than 6.0 mg/L unless background conditions are lower; natural seasonal and daily variations above this level shall be maintained;”  

At levels below 3 mg/l marine organisms exhibit signs of stress and below those levels fish kills can occur.

 The second graph shows the dissolved oxygen results as per cent saturation. Percent saturation measures DO as a percent of what the water could theoretically hold at a given temperature and salinity.  The theoretical maximum DO saturation is 100 percent. However, percent saturation values greater than 100 are common in areas with significant plant photosynthesis or in agitated waters (i.e. wind-driven).

 Not surprisingly the data near the surface indicates generally higher DO levels due to surface reaeration. Mid depth samples were taken in relatively shallow systems.

 FECAL COLIFORM

 Potential fecal coliform sources include storm water discharges(cleaning the surface of animal waste and deposition), wild life, failing septic systems, illegal boat discharges, wetland wrack (accumulated debris at high tide line) and sediment among others. All of Harwich’s shellfish resources are closed seasonally, the threshold for which is 14 CFU/100 ml versus 200 for swimming.  The simple reason for this low standard is that shellfish are filter feeders are can accumulate contamination. At the same time they have the ability to cleanse themselves if in unrestricted waters within a relatively short period of time. Which explains the ability to reopen areas seasonally or with improved conditions fairly promptly

             Past sampling by the DRN in Allen Harbor led to a detailed study4 by a consultant in 2002 to track down the more likely sources. 

 . Very high levels above the threshold for human contact have persisted above Lower county Rd for several years and appear unrelated to rainfall. The study has concluded that the prime source of the persistently high levels is raccoon feces deposited in the wetlands above LCR and Rte 28, washed into the Harbor on outgoing tides. Road runoff from Rte 28 is another major contributor but on a transitory basis. More detail is contained in that report. The latest data in figure 4 for 2003 and 2004 continues to show that pattern. Figure 5 the geometric mean for the last 3 years is a clearer picture of the pattern, with Ships Haven and Kildee Rd having persistently high counts versus the harbor proper.

  Five years of data for Wychmere Harbor , figure 6, show that it has been remarkably free of significant bacterial contamination in spite of the fact that a major storm drain from rte 28 discharges into the harbor. Continued sampling and analysis will be needed to define the existence of any problems. The data raises questions regarding the closure of shell fishing in the Harbor.  

Saquatucket Harbor (figure7) was sampled for the first time in 2002 and showed sporadic and seemingly unrelated high levels. Andrews creek had the highest and most consistent results. The last two summers were relatively dry so rainfall wasn’t a factor. The most recent data show more persistent moderately high counts.  A more detailed watershed evaluation will be required to isolate the cause, but  wild life from the contributing wetlands are a likely cause.  

Herring River is one the largest watersheds on the Cape, over 10,000 acres which starts in Long Pond, the largest pond on the Cape . It is an incredible complex fresh/salt water system, with extensive salt-water wetlands, which harbor a wonderful diversity of wildlife.  

The data (figures8, 9 ) shows high levels in the upper salt water system especially North rd and Lothrop Rd.   The data shows a definite response to rainfall events but the same levels have also been found during dry weather periods. While it is too early to draw conclusions the North rd area has no obvious sources except wildlife and Lothrop Rd has a large and varied watershed.  

References
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1        Hawich Water Quality Monitoring Program Quality Assurance Project Plan, prepared by the University of Massachusetts Dartmouth , School for Marine science and Technology,2004.

2        National Estuarine Eutrophication Assessment, Effects of Nutrient Enrichment in the Nation’s Estuaries, National Oceanic and Atmospheric Administration, 1999.

3        Baywatchers II, Nutrient related water quality of Buzzards Bay embayments: a synthesis of Baywatchers monitoring 1992-1998, Coalition for Buzzards Bay , 1999.

4        Fecal Coliform Evaluation and Mitigation Planning for the Allen’s Harbor Watershed, Town of Harwich, Massachusetts, March 2003, Sterns & Wheler Companies

5        A Baseline Hydrodynamic and water quality Investigation

6        gation of the Lower Herring River Harwich, Ma., Horsely & witten , Inc June 2000

7        Coastal Nitrogen Loading Project, final Report April 2002, Cape cod Commission, Water Resources Office

CHARTS
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APPENDIX A
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