2009 Annual Report – Merrimack River Monitoring Program

Merrimack River Watershed Council, Inc. The Voice of the Merrimack Merrimack River Monitoring Program Formerly known as the Merrimack River Water Quality Monitoring, Analyzing, Protecting and Promoting (MAPP) Program 2009 Annual Report Prepared by: Merrimack River Watershed Council, Inc. 600 Suffolk Street, 5 th Floor Lowell, MA 01854 www.merrimack.org April 22, 2010
Acknowledgements The Merrimack River Watershed Council Inc. (MRWC) would like to thank those members of the Volunteer Environmental Monitoring Network (VEMN) who have helped us collect the water quality data described in this report, including the Lowell National Historical Park. Without the dedication of these volunteers, the Merrimack River Monitoring Program, formerly known as the Merrimack River Water Quality Monitoring, Analyzing, Protecting and Promoting (MAPP) Program, would not be possible. VEMN volunteers have donated time, boats, fuel, boat ramp fees, equipment, expertise and knowledge to make this program a success. MRWC thanks you on behalf of the Merrimack River and its communities, both human and natural, for your hard work. We would also like to acknowledge the support we have received from our funders. Financial donations from Massachusetts Environmental Trust, the Stevens Foundation, the Davis Conservation Foundation, the EnTrust Fund and the Cabot Family Charitable Trust have provided the resources necessary for the continued success of the Merrimack Monitoring Program in its third year. The Environmental Protection Agency (EPA) provided the Global Positioning System units needed for this project through its equipment loan program as well as donating laboratory bacteria analysis, ammonia test strips and a surfactant test kit as an in­kind contribution. Finally, the Lowell Wastewater Treatment Utility and Waters Corporation have provided additional in­kind support for nutrient, bacteria, trace metals and pharmaceutical sample analysis. Tracie Sales Water Resources Manager Merrimack River Watershed Council, Inc.
Christine Tabak Executive Director Table of Contents Merrimack River Monitoring Program ............................................................................ 1 2009 Annual Report ....................................................................................................1 Executive Summary ........................................................................................................ 6 Introduction..................................................................................................................... 8 Characteristics of the Merrimack River........................................................................8 Baseline Monitoring Project .......................................................................................... 10 Project Location ........................................................................................................10 Methods ....................................................................................................................13 Quality Assurance/Quality Control............................................................................14 2009 Baseline Water Quality Results and Discussion ................................................17 Bacteria .................................................................................................................17 Field Study Analysis ..........................................................................................17 CSO Analysis ....................................................................................................23 Temperature ..........................................................................................................26 Dissolved Oxygen .................................................................................................28 pH .........................................................................................................................29 Specific Conductance, Total Dissolved Solids & Salinity.......................................32 Clarity ...................................................................................................................33 Continuous Water Quality Monitoring.......................................................................34 2009 Hotspot Monitoring ..........................................................................................36 Nutrients and Metals Screening ..................................................................................... 38 Methods ....................................................................................................................38 Results and Discussion ..............................................................................................39 Ammonia...............................................................................................................39 Nitrogen ................................................................................................................40 Phosphorus ............................................................................................................40 Detergents .............................................................................................................40 Metals....................................................................................................................40 Pharmaceutical Product Screening................................................................................. 42 Methods and Project Location ...................................................................................42 Pharmaceutical Screening Results and Discussion .....................................................43 Accomplishments and Next Steps.................................................................................. 45 Accomplishments ......................................................................................................45 Next Steps .................................................................................................................47 References..................................................................................................................... 49 Appendix A: Summary of Bacteria Results 2007 – 2009 .............................................. 51 Appendix B: Water Quality Tables ............................................................................... 53
2 List of Tables Table 1. List of 2009 Baseline monitoring stations in the Merrimack River. .................. 12 Table 2. List of physical water quality parameters measured.......................................... 13 Table 3. List of bacteria sampling dates by section. Bold face indicates wet weather events. ............................................................................................................ 14 Table 4. Massachusetts (MA DEP 2007) and New Hampshire (NH 1998) water quality standards. ............................................................................................ 17 Table 5. Summary of 2009 Merrimack River Baseline Water Quality Monitoring Project bacteria water quality results – percent of time the Merrimack River meets water quality standards under various criteria........................................ 18 Table 6. National and Massachusetts water quality criteria. Values are maximum allowable concentrations unless otherwise noted............................................. 39
3 List of Figures Figure 1. Map of 2009 Baseline monitoring stations on the Merrimack River. ............... 11 Figure 2. Daily precipitation (bar graph) and average daily stream flow (line graph) in the Merrimack River May through October, 2009 in Lowell, Massachusetts (USGS Undated, NOAA Undated).................................................................. 15 Figure 3. Enterococcus bacteria concentrations May through October 2009 in the Merrimack River in Section 1 between Haverhill and Newburyport, Massachusetts. Hatch pattern indicates wet weather event. Values greater than 104 cfu/100ml indicate unsafe swimming conditions............................... 19 Figure 4. E. coli bacteria concentrations in the Merrimack River between May and October 2009 in Section 2 (Haverhill to Lawrence), Section 3 (Lawrence to Lowell), Section 4 (Lowell to Tyngsborough), and Section 5 (Nashua/Hudson). See Table 3 for wet versus dry weather events. Values over the red line indicate unsafe swimming conditions according to respective state water quality standards. .......................................................... 20 Figure 5. Geometric mean of E. coli and Enterococcus bacteria concentrations May through October 2009 in the Merrimack River. Stations with less than five samples, including all those in Section 5, were not included in the geometric mean calculation. ............................................................................................ 22 Figure 6. Total daily precipitation in inches in Lowell, Massachusetts compared to days on which LRWWU CSO diversions occurred May through October, 2009................................................................................................................ 24 Figure 7. Total daily precipitation in inches in Lawrence, Massachusetts compared to days on which GLSD CSO occurred May through October, 2009. .................. 24 Figure 8. Total daily precipitation in inches in Haverhill, Massachusetts compared to days on which HWTF CSO occurred May through October, 2009. ................. 25 Figure 9. Median daily water temperature in the Merrimack River between May and October 2009 combined with the average of the mean daily air temperature for the lower Merrimack Valley (Nashua, NH and Lowell, Lawrence, Haverhill and Groveland, MA)........................................................................ 27 Figure 10. Median dissolved oxygen results by station in the Merrimack River between May and October 2009...................................................................... 28 Figure 11. Median pH at each monitoring station in the Merrimack River between May and October 2009.................................................................................... 31 Figure 12. Median specific conductance for fresh water stations in the Merrimack River between May and October 2009. ........................................................... 32 Figure 13. Percent dissolved oxygen saturation and daily precipitation in the Merrimack River’s Pawtucket Dam impoundment in Lowell, Massachusetts from September 22 through October 6, 2009................................................... 35 Figure 14. Location and range of bacteria counts for several Merrimack River hotspot samples in 2009. ............................................................................................. 37
4 Figure 15. Aluminum levels in Section 4 (Tyngsborough – Lowell) of the Merrimack River in Massachusetts on October 20, 2009. Red line indicates the EPA chronic exposure limit for aluminum in surface waters.................................... 41 Figure 16. Location of pharmaceutical sampling sites on the Merrimack River, June 24, 2009.......................................................................................................... 42 Figure 17. Pharmaceutical products found in Section 2 of the Merrimack River, June 24, 2009.......................................................................................................... 43 Figure 18. Number of pharmaceutical products found at each site Section 2 of the Merrimack River, June 24, 2009. .................................................................... 44 List of Water Quality Results Tables Bacteria Results............................................................................................................. 54 Water Temperature Results ........................................................................................... 55 Dissolved Oxygen Results ............................................................................................. 57 pH Results..................................................................................................................... 59 Specific Conductance Results........................................................................................ 61 Total Dissolved Solids Results ...................................................................................... 63 Salinity Results ............................................................................................................. 65 Nutrient Results............................................................................................................. 67 Metals Results ............................................................................................................... 68
5 Executive Summary The Merrimack River Monitoring Program is a volunteer water quality monitoring effort begun in 2007 to collect baseline water quality information in the 50­ mile mainstem of the Merrimack River in Massachusetts. Since its inception the program has expanded geographically to include monitoring in southern New Hampshire and programmatically to incorporate additional water quality parameters. In 2009 alone, 40 Merrimack Valley community members volunteered with the Merrimack River Watershed Council (MRWC) to collect water quality data at 41 sites along the length of the river. Volunteer teams monitored seven to nine sites in one of five river sections from Newburyport to Nashua, traveling from one site to another via boat. Over forty monitoring trips occurred throughout the spring, summer and fall of 2009, with bacteria samples collected on 23 of these trips, nutrient data collected on five days, pharmaceutical product samples collected once and physical water quality parameters recorded on all of the days. Physical water quality data collected includes water temperature, pH, dissolved oxygen, conductivity, total dissolved solids, salinity and Secchi depth. Physical water quality parameters met state standards with the exception of pH. On several days between May and August pH values as low as 3.2 to 4.1, the acidity of vinegar, were found in various parts of the river. Bacteria samples were collected once per month in each section and analyzed at the Region 1 EPA laboratory. In comparison to the data MRWC collected in prior years, 2009 dry weather bacteria results remained relatively consistent for the number of days the river was safe for swimming (96 percent) and boating (99 percent) according to state water quality standards where the sample was collected. In wet weather, 2009 data indicated an improvement in Merrimack River water quality: the river met state water quality standards 95 percent of the time for swimming and 100 percent of the time for boating. Evaluation of Merrimack River water quality based solely on criteria used by New Hampshire or by other Massachusetts watershed associations would indicate lower water quality, however, with only two thirds of wet weather days safe for swimming. In 2009 MRWC also had the exciting opportunity to get its new Safe Drinking Water Project off to a flying start with a screening for pharmaceutical products. Samples collected at several locations between Lawrence and Haverhill, Massachusetts, an area downstream of several drinking water sources, came back positive for 16 of 20 common drugs. A few of our 2009 discoveries and successes include:
· Septic leak in Lawrence fixed – MRWC identified a pipe discharging polluted effluent into the Merrimack River in Lawrence. By working with Massachusetts Department of Environmental Protection officials in cooperation with the City of Lawrence, the source of the leaking septic system was determined and the leak fixed.
6 · Spicket and Shawsheen Rivers contribute pollution to the Merrimack – 2009 bacteria data, supported by a geometric mean of results over the Massachusetts state water quality limit, suggests that both the Spicket and Shawsheen Rivers frequently contain high levels of bacteria. Both rivers also demonstrate significantly higher conductivity and total dissolved solids than the Merrimack mainstem. Sampling along the length the tributaries will be necessary to pinpoint specific sources.
· Merrimack River nutrient and metals monitoring begun – Nutrient and metals monitoring began in 2009 as part of the Search and Restore Project. Results collected in 2009 have provided baseline nutrient data for the river and identified critical stations to target for the wet­ and dry­weather monitoring planned for 2010. Analysis of metals in the water has also identified aluminum as a potential element of concern. The first three years of the Merrimack River Monitoring program have reestablished MRWC’s Volunteer Environmental Monitoring Network and effectively engaged local community organizations and citizens regarding water quality concerns in the river. Future plans include continuing baseline monitoring and bacteria sampling in Massachusetts and southern New Hampshire, nutrient monitoring and intensive sampling of high­use and problem sites on the river. MRWC will also continue spreading information about the work that yet needs to be done to achieve our vision of a pure Merrimack River, respected and enjoyed.
7
Introduction The Merrimack River Watershed Council, Inc. (MRWC) is a non­profit 501(c)(3) organization formed in 1976 by local activists and regional planning commissions to promote citizen involvement in the clean­up of the Merrimack River. Its organizational mission today is to ensure the sustainable ecological integrity and balanced, managed use of the Merrimack River and its watershed through science, advocacy, partnering and recreation. Our focus area is the Merrimack River Watershed mainstem and its adjoining communities in Massachusetts and New Hampshire, though we have also accomplished many projects in our eighteen sub­watersheds. We understand that we are the only third­ party advocate of the entire length of the Merrimack River in Massachusetts who is independent of commercial or regulatory interests; we are “The Voice of the Merrimack.” Since the mission of the MRWC is to ensure the integrity and balanced use of the watershed and its resources, it is imperative that we focus on the river from which our organization is named. In the past, MRWC has performed extensive projects on tributaries of the Merrimack River, while leaving the health of the Merrimack River itself relatively unchecked. In 2007, the board and staff chose to rectify this past oversight by committing to the Merrimack River Water Quality Monitoring, Analyzing, Protecting and Promoting (MAPP) Project, now renamed the Merrimack River Baseline Monitoring Project. The Baseline Monitoring Project is a three phase program designed to: (1) quantify the baseline water quality of the Merrimack River, (2) discover sources of pollution to the river, address and reduce pollution to the Merrimack River through both traditional and creative methods, and (3) educate watershed constituents on how to protect this important resource. Since 2007 MRWC’s water quality monitoring efforts have grown to become the Merrimack River Monitoring Program, encompassing the original Baseline Monitoring (MAPP) Project, the Merrimack River Search and Restore Project (formerly known as the Impairment Quantification or IQ Project), and the Safe Drinking Water Project. The main body of this report summarizes the results of the 2009 Baseline Monitoring Project, which includes recent expansion of baseline water quality monitoring into southern New Hampshire. Additional sections review the initial nutrient and metal sampling results of the first year of the two­year Search and Restore Project as well as the results of the pharmaceutical screening conducted in June 2009 as the first phase of the Safe Drinking Water Project. Characteristics of the Merrimack River The Merrimack River is 115 miles long, beginning at the confluence of the Pemigewasset and Winnipesaukee Rivers in Franklin, New Hampshire and flowing approximately 65 miles in New Hampshire and another 50 miles in Massachusetts to its mouth in Newburyport, Massachusetts. There are a total of six dams on the mainstem of the river, though only two in the stretch of river monitored by MRWC: the Essex Dam in Lawrence, Massachusetts and the Pawtucket Dam in Lowell, Massachusetts. There are two USGS gauging stations on the Merrimack River in Massachusetts, one in downtown Haverhill that measures only water height due to the influence of the tides, and one in Lowell at the confluence with the Concord River that measures stream flow. A new
8 gauging station was installed during the summer of 2009 on the Merrimack in downtown Nashua, New Hampshire. Between Newburyport and the Essex Dam in Lawrence, the river is affected by ocean tides. Salt water intrudes up the river five to ten miles depending on the tide and river volume, and the river current can reverse, depending on the height of the tide and the level of flow in the river, up to the Mitchell’s Falls area in Haverhill when the tide comes in. Water levels in the river can be tidally affected for the entire 29 miles from the estuary in Newburyport up to the Essex Dam during periods of low flow, such as during a typical August and September (M. Vets, Haverhill Harbormaster, anecdotal). In general, high tide in Haverhill lags high tide in Newburyport by approximately 1¼ hours, while low tide in Haverhill lags low tide in Newburyport by approximately 3 hours.
9 Baseline Monitoring Project Project Location The 2009 Baseline Monitoring Project collected water quality information in the mainstem of the Merrimack River in Massachusetts and southern New Hampshire. Figure 1 illustrates the 41 monitoring stations, each near an outfall, tributary or at a historical monitoring site. Monitoring occurred regularly between May and October at most of the identified sites, though data was only collected in Section 2 between June and October. Two stations in Massachusetts, 38.9 and 40.0, and five stations in New Hampshire, 51.8 through 55.9, were only monitored once due to access and boat availability difficulties. Monitoring was conducted in five river sections, with 7 to 9 sites located in each section. The river sections are: 1) the estuary in Newburyport to the Haverhill/Groveland town line, 2) Haverhill to the Essex Dam in Lawrence, 3) the Essex Dam to the Pawtucket Dam in Lowell, 4) the Pawtucket Dam to the Massachusetts/New Hampshire state border, and 5) the state border to Greeley Park in Nashua. Stations in section 5 were monitored for the first time in 2009 as the program was expanded to encompass the Nashua and Hudson area of southern New Hampshire. Two new stations were also added in section 3 in Lowell between the Pawtucket Dam and Duck Island. Because of shallow water, this area is usually inaccessible via motor boat, but can be reached by paddlers. In section 4, the station located at the Lowell water intake, only 0.2 miles upstream of the Stony Brook station, was removed and replaced with station 44.6 at the Vesper Country Club. In Section 2, station 27.8 was added at the mouth of the Shawsheen River as a result of high levels of bacteria found in hotspot (areas of known or suspected high pollution) samples collected in the tributary. Finally, station 3.8 in Newburyport was eliminated for its proximity to station 4.4 and a new station called Kimball Farm was created upstream at mile 11.8 near Rocks Village, an area that was not being tested. Table 1 lists the stations monitored in 2009.
10 Figure 1. Map of 2009 Baseline monitoring stations on the Merrimack River.
Table 1. List of 2009 Baseline monitoring stations in the Merrimack River. Section 1 2 3 4 5 Station Description Town 2.7 4.4 6.8 8.3 9.4 10.6 11.8 14.1 Newburyport Waste Water Treatment Plant Yankee Marina Powow River Artichoke River Indian River Cobbler Brook Kimball Farm Old North Canal Newburyport Newburyport Amesbury Newburyport West Newbury Merrimac Merrimac Haverhill 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 Johnson Creek Haverhill Waste Water Treatment Plant Little River Creek Brook Lucent Technologies Greater Lawrence Wastewater Treatment Plant Shawsheen River Spickett River Below Essex Dam Above Essex Dam Methuen Water Intake Bartlett Brook Fish Brook Gravel Pit Trull Brook Duck Island Concord River Oulette Bridge Groveland Haverhill Haverhill Haverhill North Andover North Andover Lawrence Lawrence Lawrence Lawrence Methuen Methuen Andover Dracut Tewksbury Lowell Lowell Lowell 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 Pawtucket Dam Rourke Bridge Stony Brook Vesper Country Club Lawrence Brook Tyngsborough (Rte. 113) Bridge Limit Brook Massachusetts/New Hampshire Border Lowell Lowell Chelmsford Lowell Tyngsborough Tyngsborough Tyngsborough Tyngsborough 49.9 50.9 51.8 52.5 53.1 54.4 55.9 Pheasant Lane Mall Spit Brook Unnamed Stream Nashua Country Club Nashua WWTP Nashua River Greeley Park Nashua Nashua Hudson Nashua Nashua Nashua Nashua
12 Methods All water quality monitoring and sampling was conducted in accordance with the procedures outlined in the Massachusetts Department of Environmental Protection (MA DEP) and the U.S. Environmental Protection Agency (EPA) approved 2007 Quality Assurance Project Plan (QAPP) for the Baseline Monitoring/MAPP Project, though data from two monitoring stations were collected via a non­motorized vessel. Details of the data collection methods and analysis can be found in the MRWC QAPP, available upon request from MRWC. Physical water quality parameters outlined in Table 2 were collected in situ with YSI 556 water quality probes and secchi disks. Measurements of all physical water quality parameters except for clarity were made beginning at the surface and extending down as far as possible without touching the bottom in one meter intervals to three meters. After the three meter measurement, the interval increased to every other meter (i.e. 5m, 7m and 9m), though in some cases a four meter reading was collected when the depth of the river was between four and five meters. In most cases, the median value of all of the depths measured at each station on each day has been reported wherever the percent difference between the median and the individual values was less than 10%. Where the percent difference between the median and individual values was greater than 10%, such as in the tidally affected portion of the river, depth data was maintained for analysis. Median data for 2009 can be found in Appendix A: Water Quality Tables. Table 2. List of physical water quality parameters measured. Parameter Water Temperature Dissolved Oxygen Specific Conductivity Total Dissolved Solids Salinity pH Clarity Equipment YSI 556 YSI 556 YSI 556 YSI 556 YSI 556 YSI 556 Secchi Disk Monitoring occurred on a total of 32 days in 2009. On seven of these days, monitoring occurred simultaneously in two or three sections:
· · · · · Section 1 – 14 days
Section 2 – 5 days
Section 3 – 7 days
Section 4 – 8 days
Section 5 – 5 days Of the 40 monitoring trips on the Merrimack River in 2009, 20 occurred on dry weather days, defined as less than 0.25 inches of precipitation falling in the 72 hours
13 prior to the monitoring day, and 20 occurred after wet weather events. Precipitation amounts were calculated for each river section based on triangulation principals using the daily totals recorded at the nearest two or three weather stations (NOAA Undated). Stations used were located in Newburyport, Groveland, Haverhill, Lawrence and Lowell, Massachusetts as well as in Nashua, New Hampshire. Figure 2 shows daily rainfall (inches) and river flow rate (cubic feet per second) in Lowell from May 1, 2009 through October 31, 2009. Bacteria grab samples were collected, generally once per month, just below the surface of the water at each station and were analyzed at the EPA Region 1 laboratory in North Chelmsford, Massachusetts. Table 3 lists the dates on which samples were collected in each section. Samples were analyzed for Escherichia coli (E. coli) in the fresh water portions of the Merrimack River from Haverhill to Nashua (sections 2 through 5) and Enterococcus in the salt water section of the river from Newburyport to Haverhill (section 1). Of the 21 days (including 27 sampling events) on which bacteria samples were collected, 11 days were considered dry weather and 10 days were considered wet weather. Wet weather dates are indicated in boldface in Table 3. Table 3. List of bacteria sampling dates by section. Bold face indicates wet weather events. Section May 5/20, 5/27 1 n/a 2 5/14 3 5/12 4 5/12 5 June July August 6/24 6/24 6/11 6/10 n/a 7/22 7/23 7/23 7/14 n/a 8/26 8/19 8/13 8/11 8/11 September October 9/23 9/16 n/a 9/8 9/8 10/28 10/27 10/19 10/20 10/20 Quality Assurance/Quality Control Quality assurance was achieved by collecting duplicate samples and readings as well as through the oversight of the Baseline Monitoring Project quality control officer. The MRWC QAPP requires that 10% of the physical water quality data collected with the YSI 556 units be duplicate measurements, and in 2009 volunteers collected 20% duplicate samples. Of the 1320 duplicate measurements collected and validated, all but 23, or less than two percent, were within the precision set for acceptable variability (10% for water temperature, 20% for the other parameters). Of these 23 measurements, 19 were collected in the Newburyport to Amesbury stretch of river where the influence of ocean water is greatest and a slight disturbance in the water as the probe passes through salt lens can alter the results dramatically. The data from these sampling points for the affected parameters (primarily salinity, specific conductivity and total dissolved solids) were not included in the analysis. Three other duplicate measurement exceptions were caused by operator error when probes lowered into the water for the first time on the trip were not given enough time for the readings to settle before the results were recorded. These measurements were removed from the data analysis as incorrectly collected data and the volunteers re­trained in the necessary collection techniques. The final excessive
14 5/1 5/13 5/25 6/6 6/18 6/30 7/12 7/24 8/5 8/17 8/29 9/10 9/22 10/4 10/16 10/28 0 45,000 40,000 1 Precipitation (Inches) 30,000 2 Precipitation Discharge 25,000 20,000 3 15,000 4 Daily Mean Flow (Cubic Feet/Sec.) 35,000 10,000 5,000 5 0 Figure 2. Daily precipitation (bar graph) and average daily stream flow (line graph) in the Merrimack River May through October, 2009 in Lowell, Massachusetts (USGS Undated, NOAA Undated).
variance in the duplicate data occurred for a salinity reading taken in fresh water where the value was at the extreme low end of the equipment’s detection limit. The 0.01 ppt difference between the original and duplicate values has been deemed insignificant despite the mathematical calculation that causes the difference to appear significant. Quality control for water clarity was achieved by having two volunteers observe the depth of the Secchi disk on 100% of the readings. Because Secchi depth readings can vary significantly depending on whether the readings were taken in sunshine versus shade, on smooth water versus choppy water, or in calm water versus a strong current, Secchi depth data analysis is not being included in this report except on an anecdotal basis. While attempts are made to make measurements as consistent as possible, MRWC has determined that the Secchi disks are not only difficult to use but the results are also inconclusive in a river with a strong current. Volunteers also collected a duplicate sample for bacteria analysis on each sampling trip at one of the monitoring stations visited, with 11% of all samples being duplicates. For all but five duplicate bacteria samples, results fell within of the acceptable precision range of 30% for log transformed data. For those five duplicates outside of the acceptable range, all concentrations were within the water quality limits set for safe swimming, and four of the five were very low values. With very low values, the relative percent difference technique used for quality assurance/quality control comparison is less effective because a small difference in values becomes a large percent difference. Because these four samples contained small bacteria concentrations only slightly above the minimum detection limits [the least number of colonies that can be counted: four colony forming units per 100 milliliters of water (cfu/100ml) for E. coli and ten cfu/100ml for Enterococcus], MRWC assumes that this data is valid. The fifth duplicate sample outside of acceptable precision was an Enterococcus sample collected at station 2.7 near the outfall of the Newburyport wastewater treatment plant. Given reports of a strong current at the sampling site on that day and the location near the treatment plant outfall, the variation in the primary and duplicate samples may be due to natural variation in an area where mixing would be incomplete. For analytical purposes, the concentrations of all of the primary and duplicate samples have been averaged. One duplicate E. coli sample collected in Section 3 was not listed on the data sheets and thus there was no record of the site at which it was collected. All bacteria samples collected on that day had concentrations well below the state water quality standards, however, and at only one station would the difference between the original sample and the duplicate have exceeded the acceptable precision range. Therefore, bacteria data collected on this day is still considered valid. Data collection and data entry procedures were overseen by the Baseline Monitoring Project quality control officer. Data collection methods were deemed acceptable, and any errors in data entry were corrected. More details about the quality assurance practices for the project can be found in the MRWC QAPP, available upon request from MRWC.
16 2009 Baseline Water Quality Results and Discussion The Merrimack River is designated as a Class B (freshwater) warm water fishery in New Hampshire and in Massachusetts from the New Hampshire state border to Haverhill and a Class SB (tidally affected) water body from Haverhill to the estuary in Newburyport. This means that the river is expected to support fish, aquatic life and other wildlife as well as be suitable for primary (swimming) and secondary (boating) contact. Class B waters should also be suitable as a drinking water supply with adequate treatment, while Class SB waters should support conditional shellfish harvesting (MA DEP 2007). For this type of water body, each state has set limits for the amount of bacteria the water can safely contain, the maximum water temperature, the amount of dissolved oxygen in the water and the pH. These limits are listed in Table 4. Table 4. Massachusetts (MA DEP 2007) and New Hampshire (NH 1998) water quality standards. Parameter MA Limit 235 (swim) single sample E. coli 126 (swim) geometric mean (fresh water bacteria, 1260 (boat)* 10% samples cfu/100 mL) 630 (boat)* geometric mean 104 (swim) single sample Enterococcus 35 (swim) geometric mean (salt water bacteria, 350 (boat)* 10% samples cfu/100 mL) 175 (boat)* geometric mean < 28.3°C Class B warm Water Temperature < 29.4°C Class SB Dissolved Oxygen > 5.0 mg/l pH 6.5 < pH < 8.3 Class B 6.5 < pH < 8.5 Class SB NH Limit 88 (swim) single sample 47 (swim) geometric mean 406 single sample 126 geometric mean N/A Supportive of Class B uses > 75% saturation > 5.0 mg/l during CSOs 6.5 < pH < 8.0 Class B N/A * Bacteria safety limits for secondary contact/boating are based on Massachusetts Class C waters. Bacteria FIELD STUDY ANALYSIS Measurements of Escherichia coli (E. coli) and Enterococcus bacteria are used by the states of Massachusetts and New Hampshire to determine human health risks from primary (swimming) and secondary (boating) contact in fresh and salt waters, with E. coli used in fresh water and Enterococcus used in salt water. Both E. coli and Enterococcus are bacterium commonly found in the waste of warm­blooded animals. While these strains of bacteria have not been identified as directly causing adverse health effects, they do indicate that other, more harmful, strains of bacteria are likely present. The states use two different standards to evaluate bacterial water quality, and also use different standards depending on the number of samples collected at the site. For class B (fresh) waters in Massachusetts “the geometric mean of all E. coli samples taken within the most
17 recent six months shall not exceed 126 colonies per 100 ml typically based on a minimum of five samples and no single sample shall exceed 235 colonies per 100 ml…” (MA DEP 2007). For Massachusetts class SB (salt) waters “no single Enterococci sample taken during the bathing season shall exceed 104 colonies per 100ml and the geometric mean of the five most recent samples taken within the same bathing season shall not exceed 35 Enterococci colonies per 100ml” (MA DEP 2007). New Hampshire standards are more strict for fresh water where “designated beach areas shall contain not more than a geometric mean based on at least 3 samples obtained over a 60­day period of 47 Escherichia coli per 100 milliliters, or 88 Escherichia coli per 100 milliliters in any one sample” (NH 1998), but are the same for salt water, though the Merrimack watershed is entirely fresh water in New Hampshire. Of the samples MRWC collected during dry weather in 2009, the Merrimack River met single sample bacteria water quality standards for swimming 96 percent of the time and 99 percent of the time for boating. According to the samples MRWC gathered during wet weather, the river met single sample water quality standards 95 percent of the time for swimming and 100 percent of the time for boating. Figures 3 and 4 illustrate the 2009 single sample bacteria counts at each station for Enterococcus in Section 1 and for E. coli in Sections 2, 3, 4 and 5, respectively. In these calculations, Massachusetts water quality standards were used for those samples collected in Massachusetts while New Hampshire standards were used for samples gathered in that state. Table 5 summarizes the 2009 bacteria water quality results under these state standards as well as under the two more protective standards described below. Table 5. Summary of 2009 Merrimack River Baseline Water Quality Monitoring Project bacteria water quality results – percent of time the Merrimack River meets water quality standards under various criteria. State Single Sample NH Standards CRWA Standards Weather Swim Boat Swim Boat Swim Boat Dry 96% 99% 85% 99% 74% 99% Wet 95% 100% 68% 98% 61% 98% If New Hampshire’s water quality standards were used for bacteria results in both Massachusetts and New Hampshire, water quality in the Merrimack would appear to be lower. Using the E. coli 88 cfu/100ml standard for swimming and 406 cfu/100ml standard for boating in both states, while maintaining the Enterococcus 104 cfu/100ml (swimming) and 350 cfu/100ml (boating) standards, the 2009 data MRWC collected during dry weather indicates that the Merrimack River met bacteria water quality standards for swimming only 85 percent of the time but still met standards for boating 99 percent of the time. Similarly, MRWC wet weather samples under the New Hampshire criteria suggest that the river met water quality standards just 68 percent of the time for swimming but 98 percent of the time for boating.
18 200 Enterococcus Concentration (cfu/100ml) 175 150 May June July August September October 125 MA State Limit for Swimming = 104 100 75 50 25 0 14.1 Haverhill 11.8 10.6 9.4 8.3 Station 6.8 4.4 2.7 Newburyport Figure 3. Enterococcus bacteria concentrations May through October 2009 in the Merrimack River in Section 1 between Haverhill and Newburyport, Massachusetts. Hatch pattern indicates wet weather event. Values greater than 104 cfu/100ml indicate unsafe swimming conditions.
1600 May June July August September October 1400 E. coli Concentration (cfu/100ml) 1200 1000 800 600 400 State Limits for Swimming: MA = 235 200 NH = 88 .8
16
.8
17
.1
19
.3
22
.6
25
.9
26
.8
.2
Lawrence 27
28
.6
.1
29
29
.4
31
.2
.4
Station 32
33
.1
35
.2
36
.9
37
.9
Lowell 38
.0
40
.1
41
.4
42
.4
43
.4
.6
44
46
.3
47
.9
.6
Nashua 48
.9
49
49
50
.9
0 Haverhill Figure 4. E. coli bacteria concentrations in the Merrimack River between May and October 2009 in Section 2 (Haverhill to Lawrence), Section 3 (Lawrence to Lowell), Section 4 (Lowell to Tyngsborough), and Section 5 (Nashua/Hudson). See Table 3 for wet versus dry weather events. Values over the red line indicate unsafe swimming conditions according to respective state water quality standards.
The Charles River Watershed Association (CRWA) uses the Massachusetts geometric mean bacteria limits, 126 cfu/100ml for E. coli, on single sample bacteria results rather than the single sample criteria, 235 cfu/100ml for E. coli, to determine whether or not the Charles River is safe for swimming or boating, arguing that these lower limits are more protective of human and river health (CRWA 2009). Under these criteria, assuming a similar use of the geometric mean limit of 35 cfu/100ml for single Enterococcus samples, the 2009 data MRWC collected during dry weather indicates that the Merrimack River met bacteria water quality standards for swimming only 74 percent of the time but still met standards for boating 99 percent of the time. Similarly, MRWC wet weather samples under the CRWA criteria suggest that the river met water quality standards just 61 percent of the time for swimming but 98 percent of the time for boating. Because MRWC was able to collect at least five samples at most Massachusetts stations in 2009, we were also able to calculate the geometric mean of bacteria counts for each station. Based on the 2009 geometric mean calculations, water quality at six stations exceeded Massachusetts state standards. As shown in Figure 5, three of these stations are located in Section 2, all of them at the mouth a major tributary (Spicket, Shawsheen and Little Rivers). Both the Spicket and Shawsheen Rivers have demonstrated water quality problems in the past and need to be monitored more intensely to track pollution sources within them. The Little River has not traditionally shown significant water quality problems, and the geometric mean exceedance may be the result of just one very dirty sample. Three additional stations in Section 1 exceeded Massachusetts state water quality standards for Enterococcus levels. Each of these stations is located in the upstream, fresh water portion of the section just downstream of Haverhill. New Hampshire bacteria standards for geometric mean calculations require at least three samples collected within a 60 day period. Since MRWC collected bacteria data only once per month in 2009, data frequency is insufficient for geometric means at the New Hampshire stations. In comparison to the sample data MRWC collected in 2007 and 2008, water quality in the Merrimack River seems to be generally improving during wet weather but diminishing, at least according to the more protective New Hampshire and CRWA standards, during dry weather. In general, the amount of bacteria in our samples has decreased. For example, the highest bacteria count MRWC collected in 2007 was 191,800 cfu/100 ml, but the highest collected in 2009 was only 1580 cfu/100 ml. The improvement during wet weather is probably the result of fewer combined sewer overflows (CSOs) throughout the river as cities such as Nashua, Lowell and Lawrence add stormwater treatment facilities, increase overall treatment capacity, and separate stormwater and septic sewer systems. The cause of the increase in dry weather bacteria amounts is currently unknown, but possibilities include an increasing number of failing septic systems and sewer pipes, more illicit connections whose discharges are no longer masked by CSOs, increased contamination from wildlife feces or a host of other potential causes. Additional data is required to determine if this trend is statistically significant. Appendix A summarizes the bacteria results from 2007 through 2009.
21 200 Mean Concentration (cfu/100ml) 175 150 MA State Limit = 126 cfu/100ml (E. coli ) 125 100 75 MA State Limit = 35 cfu/100ml (Enterococcus ) 50 25 .1
17
.8
16
.8
14
.1
11
.8
10
.6
9.
4 8.
3 6.
8 4.
4 2.
7 .3
19
.6
22
.9
25
.8
Station 26
.2
27
.1
28
.6
29
.4
29
.2
31
.4
32
.1
33
.2
35
.9
36
.1
37
.4
41
.4
42
.6
43
.4
Tyngsborough 44
.3
46
.9
47
48
49
.6
0 Newburyport Figure 5. Geometric mean of E. coli and Enterococcus bacteria concentrations May through October 2009 in the Merrimack River. Stations with less than five samples, including all those in Section 5, were not included in the geometric mean calculation.
CSO ANALYSIS One of the goals of the MRWC’s water quality monitoring is to begin determining sources of bacteria contamination to the Merrimack River. Because most of the samples collected over the past three years that exceed state water quality standards were collected during wet weather, project results indicate that most bacteria pollution in the river occurs during rain storm and snow melt events. Unfortunately, the effort to identify point versus non­point sources of pollution is hampered by frequent combined sewer overflow (CSO) activity in the river, causing non­point source concentrations to be obscured by CSOs and treatment plant bypasses in the five Merrimack River CSO communities of Manchester and Nashua, New Hampshire and Lowell, Lawrence and Haverhill, Massachusetts. While the Massachusetts CSO communities have been very helpful about providing data on CSO occurrences, the New Hampshire communities do not have this information available. The Lowell Regional Wastewater Utility (LRWWU), the Greater Lawrence Sanitary District (GLSD), and the Haverhill Wastewater Treatment Plant (HWTP) each reported CSO events during the monitoring season of May through October. Lawrence had the fewest with six days of CSO events during the monitoring season, Haverhill had 25 days (with one additional unconfirmed event on August 29), and Lowell had 28 days. For Lawrence and Lowell, these numbers were an improvement on the number of CSOs that occurred during the monitoring season in 2008. Between May and October 2008, GLSD reported 11 CSO days, HWTP reported 14 CSO days, and Lowell reported 33 CSO days. Figure 6 shows the Lowell daily rainfall and the days on which CSOs occurred in the Lowell area between May and October 2009. During this six month period, any local daily rainfall of more than three quarters of an inch caused a CSO in Lowell, and any daily rainfall amount over half an inch would have an 89 percent probability of causing an overflow (LRWWU 2010). While these numbers are disturbing to those using the river for swimming, boating and as a drinking water supply, they are a significant improvement over 2008 statistics. In 2008, a mere one third of an inch of rain was guaranteed to cause a CSO, and just a quarter inch would cause one 90 percent of the time. Figures 7 and 8 show similar rainfall and CSO information for GLSD in the Lawrence area and HWTP in Haverhill, respectively. The majority of events in Lawrence occurred when there was greater than one inch of rainfall in a day; however, as is evident from the June 12 rainfall, over an inch and a half of rain will not necessarily cause a CSO. In the case of GLSD, the intensity of rainfall and antecedent conditions are equally critical factors when attempting to predict overflows. The Haverhill sewer system appears shows similar characteristics to that of Lowell in that CSO events generally occurred when there was greater than one half inch of rain over the course of the prior day, and less rain was necessary to trigger CSOs when the system was recovering from previous rainfall.
23 2.5 Precipitation CSOs Lowell Total daily rainfall (inches) 2.0 1.5 1.0 0.5 0.0 5/1 5/15 5/29 6/12 6/26 7/10 7/24 8/7 8/21 9/4 9/18 10/2 10/16 10/30 Date Figure 6. Total daily precipitation in inches in Lowell, Massachusetts compared to days on which LRWWU CSO diversions occurred May through October, 2009. 2.5 Precipitation CSOs Lawrence Total daily rainfall (inches) 2.0 1.5 1.0 0.5 0.0 5/1 5/15 5/29 6/12 6/26 7/10 7/24 8/7 8/21 9/4 9/18 10/2 10/16 10/30 Date Figure 7. Total daily precipitation in inches in Lawrence, Massachusetts compared to days on which GLSD CSO occurred May through October, 2009.
24 2.5 Precipitation Confirmed CSOs Unconfirmed CSO Haverhill Total daily rainfall (inches) 2.0 1.5 1.0 0.5 0.0 5/1 5/15 5/29 6/12 6/26 7/10 7/24 8/7 8/21 9/4 9/18 10/2 10/16 10/30 Date Figure 8. Total daily precipitation in inches in Haverhill, Massachusetts compared to days on which HWTF CSO occurred May through October, 2009. An example of the complications inherent in tracing bacteria sources in the presence of CSOs can be seen in the analysis of the highest bacteria concentration MRWC found in the Merrimack River in 2009. The sample was collected at station 19.1 on September 16 th , a dry weather day, near the mouth of the Little River in downtown Haverhill. The E. coli concentration of 1580 cfu/100 ml exceeded not only safe swimming standards, but also safe boating standards. Oddly, it was also the only sample collected in Section 2 on that day that contained high bacteria levels. Normally analysis would suggest the high bacteria concentration was due to a local source or illegal boat bilge dump and MRWC would schedule hotspot (areas of known or suspected high pollution) sampling in the area to determine if there was a chronic problem. However, a review of the CSO data indicates that GLSD experienced a CSO on September 12 th as a result of a brief but intense storm producing 1.5 inches of rain. Given the distance between the GLSD outfall and station 19.1 combined with the rates of flow during the four days between when the CSO occurred and the bacteria sample was collected, it is possible that the high bacteria counts were caused by the CSO. Under normal circumstances, a pollution plume will have dispersed sufficiently over the course of four days to have caused high bacteria counts at multiple monitoring stations, suggesting the source to be local to downtown Haverhill, but the presence of the Lawrence CSO cannot be fully discounted. As a result, MRWC is unable to determine the cause of the pollution, but will continue monitoring the location.
25 Temperature None of the water temperature readings collected in 2009 exceeded the Massachusetts state maximum temperature limit for Class B warm (28.3°C) or Class SB (29.4°C) waters. Frequent rain storms, especially during the first half of the 2009 monitoring season, resulted in higher average flows in 2009 (9,110 cu. ft./sec.) than during the same months in 2007 (5,251 cu. ft./sec.) or 2008 (8,479 cu. ft./sec.), reducing the amount of time water remained in the river exposed to sunlight and heating. Mean discharge May to October is approximately 5,448 cu. ft./sec. at the Merrimack River gauge in Lowell, Massachusetts, based on data collected from 1923 through 2009 (USGS undated). Water temperature in the Merrimack River followed the expected trend of heating during the warm summer months and cooling as the days shortened and the average air temperature cooled through the fall (Figure 9). The graph demonstrates the influence that warmer air temperatures have on the river, which is of concern as a result of the expected trend of temperature increases as a result of global warming. While the Merrimack is considered a warm water fishery, historically it has provided access to cold water streams and spawning habitat for anadromous fish and must remain cool enough for both the resident and transient fish and wildlife who depend on it for survival. .
26 30 25 Temperature (C) 20 15 10 Air Temperature Water Temp. Section 1 Water Temp. Section 2 Water Temp. Section 3 5 Water Temp. Section 4 Water Temp. Section 5 0 5/1 5/21 6/10 6/30 7/20 8/9 8/29 9/18 10/8 10/28 Date Figure 9. Median daily water temperature in the Merrimack River between May and October 2009 combined with the average of the mean daily air temperature for the lower Merrimack Valley (Nashua, NH and Lowell, Lawrence, Haverhill and Groveland, MA).
Dissolved Oxygen No 2009 dissolved oxygen (DO) readings were under the water quality limit of 5 mg/l for warm water fisheries. In addition, Figure 10 shows that DO followed the expected seasonal trend of decreasing as the water increased and increasing again in the fall as water temperatures decreased. DO values collected on August 1, 2009 in Section 3 of the Merrimack River did not follow this trend, but this data was collected the day after a heavy storm, when increased river flow can add oxygen to the water. On August 26, 2009, dissolved oxygen readings throughout the monitoring trip in Section 1 were below normal for the Merrimack River. Many of the measurements were below 6.5 mg/l, and two taken at the Newburyport Wastewater Treatment Facility were slightly below 6.0 mg/l. Measurements of other water quality parameters that day were normal for fresh water at that time of year, though water temperatures that day were among the highest recorded during the 2009 monitoring season. 12 Dissolved Oxygen (mg/l) 10 8 6 Water Quality Limit = 5 mg/l 4 Section 1 Section 2 Section 3 2 Section 4 Section 5 0 5/1 5/21 6/10 6/30 7/20 8/9 8/29 9/18 10/8 10/28 Date Figure 10. Median dissolved oxygen results by station in the Merrimack River between May and October 2009.
28 pH During the summer of 2009, MRWC water quality monitors measured unusually low pH values in the Merrimack River in Massachusetts. As apparent in Figure 11, pH values on four separate days, May 20 in Section 1, May 30 in Section 3, August 1 in Section 3, and August 19 in Section 4, were found to be well below the lower limit of 6.5 standard units set by the state for conditions acceptable in Class B waters. The pH of the Merrimack River water measured on these four days is equivalent to the pH of vinegar. The data has been reviewed for potential equipment malfunction and while it does not appear that the observed readings were in error, the possibility cannot be completely eliminated. On two occasions the low pH readings were confirmed using pH test strips. MRWC has consulted with MA DEP, EPA, U.S. Fish and Wildlife Service, and municipal water treatment plant officials regarding the pH results we recorded. None of the water quality experts contacted has been able to offer an explanation for the extremely low measurements found. On May 20, 2009, MRWC staff and volunteers monitored in Section 1 from Old North Canal in Haverhill to the Newburyport Wastewater Treatment Plant. At the Old North Canal site (station 14.1), pH values around 3.0 to 3.5 were observed and thought to be erroneous; therefore, they were not recorded. Calibration of the pH probe was checked and found to be within tolerance. Values observed at the next station downstream ranged from 3.3 to 3.5. From that point, pH values gradually increased at each station as the team headed downstream, rising from 5.2 at Cobbler Brook (station 10.6); to 7.0 at the Newburyport Wastewater Treatment Plant (station 2.7). During the return trip upstream, the team collected another pH reading as well as a sample of water at a point between stations 11.8 and 10.6. The pH at this site was 5.8, and the water sample, evaluated with a volunteer’s swimming pool test strips, confirmed the low pH readings. On May 30, 2009, MRWC staff and volunteers monitored in Section 3 from above the Essex Dam in Lawrence to Duck Island in Lowell. pH in this section of the Merrimack River ranged from 4.1 to 6.2 with the lowest values found at Fish Brook (station 33.4) and Trull Brook (station 36.3) and the highest values found at Bartlett Brook (station 32.2) and the Methuen Water Intake (station 31.4). Changes in pH from one site to another did not demonstrate any particular trend, unlike the data collected on May 20 th where pH consistently increased as the team moved downstream. On August 1, 2009, MRWC volunteers again monitored in Section 3 from above Essex Dam to Trull Brook. On this day pH ranged from 3.3 at five meters depth to 6.4 at the surface at the Methuen Water Intake (station 31.4). Low pH values were recorded at several other sites as well, but none demonstrated the extreme range of station 31.4. On August 19, 2009, MRWC interns and volunteers monitored at the Lowell Motor Boat Club near station 41.1 and in the Pawtucket Canal. During this monitoring event, pH ranged from 3.2 in the Merrimack River at the Lowell Motor Boat Club to 6.5 at the Swamp Locks in the canal, though pH varied significantly by depth at most sites.
29 The monitoring equipment was checked with pH 4.0 buffer solution after the first station and found to be properly calibrated. A few hours later, MRWC interns returned to the Lowell Motor Boat Club to check pH values, monitoring from the shore with a seven meter extension pole. Here pH ranged from 6.5 at the surface to 3.6 at one meter depth to 4.8 at two meters depth. pH test strips confirmed the results found using the YSI 556 water quality meters. Eight days later, EPA sampled in the same area and found that pH had returned to normal levels. All of the pH results over the neutral value of 7 shown in Figure 12 were recorded in Section 1 and are due to the influence of salt water, which has a higher pH than fresh water, at Stations 2.7 through 8.3. Salt water rarely extends as far upstream as Station 8.3 at the mouth of the Artichoke River, but tides were unusually high the night of August 19, 2009 and salt water was still draining out of the tributary and tidal wetlands surrounding Station 8.3 on the morning of August 20 th , resulting in higher salinity and pH values at that station than typical.
30 9 Upper Limit MA Salt Water Upper Limit MA Fresh Water 8 Upper Limit NH pH 7 6 Lower Limit MA & NH 5 Section 1 Section 2 Section 3 4 Section 4 Section 5 3 5/1 5/21 6/10 6/30 7/20 8/9 8/29 9/18 Date Figure 11. Median pH at each monitoring station in the Merrimack River between May and October 2009.
10/8 10/28 Specific Conductance, Total Dissolved Solids & Salinity Specific conductance, total dissolved solids (TDS) and salinity are highly correlated in the 2009 water quality monitoring results, and are thus addressed together. Because of the complications due to salt water intrusion in Section 1 between Newburyport and Amesbury, conductivity, TDS and salinity can not be easily analyzed relative to data collected up stream in the Merrimack River and is therefore treated separately. Neither Massachusetts nor New Hampshire has explicit water quality standards for specific conductance, TDS or salinity. However, high levels of these parameters in fresh water are indicative of chemical (ionic) activity in the water column including suspended or dissolved particles such as metals and salts. Figure 12 shows the median conductivity for each station on each day, identified by river section. In general, results of our monitoring showed very little variation within each monitoring day for specific conductance, TDS and salinity in Sections 3, 4 and 5 and in the fresh water portions of Section 1. In Section 1, the exception to this rule of little daily variation is data collected on August 20 th near the mouth of the Artichoke River. As mentioned previously, the water in this area had unusually high specific conductance, TDS and salinity, most likely due to a very high tide the night before. 600 Section 1 Section 2 Section 3 Section 4 Section 5 Specific Conductance (uS/cm) 500 400 300 200 100 0 5/1 5/21 6/10 6/30 7/20 8/9 Date 8/29 9/18 10/8 10/28 Figure 12. Median specific conductance for fresh water stations in the Merrimack River between May and October 2009.
32 In Section 2, specific conductance, TDS and salinity results from stations 16.8 to 26.9 and station 29.1 were all very similar each day. However, data collected at station 27.8 at the mouth of the Shawsheen River, illustrated with a red outline around the blue squares in Figure 13 above, was inconsistent, showing much higher conductance than typical in the Merrimack River. Average specific conductance at the mouth of the Shawsheen River was 469 μS/cm, approximately 300 μS/cm higher than typical conductance values measured in the Merrimack. Because this was the first year MRWC monitored regularly at the mouth of the Shawsheen River, we are unable to compare these results to prior year averages, but the results are consistent with two hotspot measurements collected in 2008. Conductance measured at the mouth of the Spicket River also tended to be higher on average than in the Merrimack mainstem, though the average difference was only about 50 μS/cm. In general, conductivity, TDS and salinity tend to be slightly higher in the Merrimack River’s tributaries than in the mainstem. The water in Newburyport and upstream into Amesbury is a mixture of salt and fresh water, with the extent of the salt water effect depending on the tide. Data collected within the first eight miles of the river showed expected increases in salinity with proximity to ocean, depth (salt lens), river discharge volume and tidal influences. Graphs for TDS and salinity show similar patterns and trends to the specific conductance graph in Figure 13 and are available upon request. Clarity Turbidity is a measure of the clarity of the water. MRWC collected turbidity information by lowering a Secchi disk into the water to the point that it could just barely be seen, and then recording the depth of the disk to the nearest 0.1 meter. Some stations, especially those in between Haverhill and Lawrence, were consistently too shallow to measure Secchi depth. At other times, strong river currents would pull the disk downstream making an accurate secchi depth reading impossible. For the secchi depth measurements made, however, no obvious trends in water clarity were apparent, either over time or at individual monitoring stations. Mean clarity in the Merrimack River increased in 2009 to 1.8 ± 0.4 m compared to 2008 (1.5 ± 0.5 m), but remained less than in 2007 (2.0 ± 0.7 m).
33 Continuous Water Quality Monitoring In order to obtain a better understanding of the daily changes in dissolved oxygen and other parameters occurring in the Merrimack River, MRWC conducted continuous water quality monitoring over the course of two weeks in 2009. A YSI 556 meter was installed on a Lowell Motor Boat Club dock located in the impoundment of the Pawtucket Dam in Lowell, Massachusetts. Sensors were positioned at one­meter depth off the end of the floating dock such that the depth would remain at one meter despite changes in the river height. The handheld display unit was hidden to prevent tampering or theft. Water temperature, dissolved oxygen, total dissolved solids, conductivity, pH and barometric pressure were recorded every ten minutes beginning the afternoon of September 22, 2009 and ending the morning of October 5 th . River flow at the site was deemed sufficient, despite its location in the dam impoundment, to provide a continuous supply of fresh water, eliminating the problem of oxygen depletion at the DO probe interface. As expected, water temperature, dissolved oxygen and pH exhibited diurnal fluctuations, with highest values just before sunset and lowest values before sunrise. In contrast, specific conductance and total dissolved solids remained relatively constant throughout the day. Figure 13 illustrates the diurnal change in dissolved oxygen saturation as well as a trend toward reduced oxygen saturation over the course of the continuous monitoring period. The average daily fluctuation in DO was 0.6 mg/l, or 8% saturation. The average difference between the nighttime low DO reading to the 9:30 AM measurement was 0.3 mg/l (3%). In prior years, MRWC has recorded DO levels below 6 mg/l at station 41.1, only a few meters away from the Lowell Motor Boat Club docks. Measurements of DO collected at station 41.1 are typically made around 9:30 AM. Low past measurements combined with the knowledge that the lowest daily DO levels were likely 0.3 mg/l or more lower leads to concerns that the Merrimack River may not be fully supportive of aquatic life during some parts of the year. While the downward trend in percent saturation is consistent during dry weather, the trend is interrupted each time it rains. Dissolved oxygen and DO saturation both increased slightly following rain events. Presumably the rain water itself combined with higher flows resulting from the rain increases the amount of dissolved oxygen in the water.
34 105% 0.50 0.45 100% 0.35 95% 0.30 90% 0.25 0.20 Precipitation (in) Dissolved oxygen (% saturation) 0.40 85% 0.15 0.10 80% 0.05 Dissolved Oxygen (% saturation) Daily Precipitation 75% 9/22 0.00 9/23 9/24 9/25 9/26 9/27 9/28 9/29 9/30 10/1 10/2 10/3 10/4 10/5 10/6 Date Figure 13. Percent dissolved oxygen saturation and daily precipitation in the Merrimack River’s Pawtucket Dam impoundment in Lowell, Massachusetts from September 22 through October 6, 2009.
35 2009 Hotspot Monitoring In addition to the regularly scheduled, boat­based monitoring conducted between May and October, MRWC and volunteers also conducted hotspot monitoring on the Merrimack and its tributaries in order to identify potential or quantify known sources of pollution. Hotspot monitoring occurred between March and October of 2009 in response to three situations: (1) a tributary, pipe and drainage­way water quality survey of water sources to the Merrimack River, (2) sampling of a suspected problem site, and (3) follow­ up sampling of a known problem location. Discharge survey samples were collected by a volunteer on foot in Andover, Methuen, Lawrence, North Andover and Haverhill. This survey is a continuation of an effort begun in 2007 to sample all of the flows into the Merrimack River in Massachusetts. Sampling of suspected and known problem sites were sometimes done on foot and other times by boat, particularly when regular monitoring teams noticed an unusual discharge. Overall, nearly 50 hotspot bacteria samples were collected and analyzed in 2009. As shown in Figure 14, several of the highest hotspot bacteria levels were found in Methuen and Lawrence, with one E. coli count of 92,080 cfu/100ml in Methuen and another in Lawrence of 8,130 cfu/100ml. Both of these sites were reported to the MA DEP Bacteria Source Tracking Team, which proceeded with additional sampling, dye tracing from potential sources, and enforcement action. Once notified of the problem, the city of Lawrence cooperated with MA DEP officials to find and correct the source of sewage leaking into a stormwater pipe next to the Bashara boathouse. As of late in 2009, however, the bacteria source in Methuen had not been traced to its source. MRWC also followed up on one of the problem sites identified on the Powwow River during the 2008 monitoring season. Bacteria levels at one outfall into the tributary had E. coli levels of 198,630 cfu/100 ml in 2008, and MA DEP had issued a Notice of Non­compliance to the Town of Amesbury instructing the town to correct the problem. An E. coli sample collected from the pipe on October 21, 2009 and containing 41,060 cfu/100 ml suggests that as of that time, the problem had not yet been corrected.
36 Figure 14. Location and range of bacteria counts for several Merrimack River hotspot samples in 2009.
37 Nutrients and Metals Screening Methods MRWC staff, interns, and volunteers screened for nutrients, detergents, and metals on several occasions in 2009 at multiple sampling locations on the Merrimack River, its tributaries and outfall pipes. Three different data collection methods were used: (1) Ammonia & Detergents (September 16 & October 21, 2009) ­ Grab samples were collected at several Section 2 monitoring stations and Section 1 and 2 outfalls. Hach ammonia (NH3­N) test strips and a Hach surfactant (alkylbenzene sulfonate) test kit provided by EPA were used to analyze for ammonia and detergents. (2) Nutrients, Metals & Bacteria (October 20, 2009) ­ Grab samples were collected at Section 4 mainstem monitoring stations and analyzed by New England Testing Laboratory for nutrients [ammonia as N, total Kjeldahl nitrogen (TKN), nitrate as N, and total phosphorus], metals (aluminum, arsenic, cadmium, chromium, copper, iron, lead, nickel, and zinc) and E. coli. Metals samples were preserved using nitric acid provided by the lab, and E. coli samples were preserved using sodium thiosulphate tablets. All samples were preserved on ice until analysis. Sample analysis was funded by the Lowell Regional Wastewater Utility. (3) Ammonia (November 13­17, 2009) – MRWC interns working with University of Massachusetts Lowell students collected in situ measurements of ammonia and ammonium with a YSI 6920 multiparameter sonde at eight locations in Sections 3 through 5 in the Merrimack River and its tributaries. Neither federal nor Massachusetts state standards exist for many nutrients and metals commonly monitored in surface waters. According to Massachusetts Surface Water Quality Standards, “[u]nless naturally occurring, all surface waters shall be free from nutrients in concentrations that would cause or contribute to impairment of existing or designated uses and shall not exceed the site specific criteria developed in a TMDL [Total Maximum Daily Load] or as otherwise established by the Department pursuant to 314 CMR 4.00” (MA DEP 2007). Guidelines for ammonia vary depending on the presence or absence of salmonid fish, their respective life stages, pH, and water temperature (EPA 2010). Since the Merrimack River has historically supported salmonid populations, the most protective standards were applied for ammonia. For other nutrient parameters, MRWC has used the official and unofficial guidelines that apply best to the Merrimack River as outlined in Table 6. For metals, acute and chronic exposure limits have been set by EPA.
38 Table 6. National and Massachusetts water quality criteria. Values are maximum allowable concentrations unless otherwise noted. Parameter Acute Chronic Units Source Aluminum* 0.750 0.087 mg/L EPA 2009 Arsenic 0.340 0.150 mg/L EPA 2009 Cadmium 0.002 0.00025 mg/L EPA 2009 Chromium (III) 0.570 0.074 mg/L EPA 2009 Chromium (VI) 0.016 0.011 mg/L EPA 2009 Chromium, Total Unspecified Copper** Calculated Iron mg/L EPA 2009 1.000 mg/L EPA 2009 Lead 0.065 0.0025 mg/L EPA 2009 Nickel 0.470 0.052 mg/L EPA 2009 Zinc 0.120 0.120 mg/L EPA 2009 mg/L EPA 2009 Ammonia*** Nitrate (N­NO3) Nitrite as N Total Kjeldahl Nitrogen as N Phosphorus (total) 0.36 ­ 7.03 0.310 0.310 mg/L CRWA 2009 Unspecified Unspecified 0.050 0.050 mg/L Meek 2009 * For pH range 6.5 – 9.0 ** Calculated using Biotic Ligand Model (BLM) (EPA 2009). “The BLM requires ten input parameters to calculate a freshwater copper criterion (a saltwater BLM is not yet available): temperature, pH, dissolved organic carbon (DOC), calcium, magnesium, sodium, potassium, sulfate, chloride, and alkalinity” (EPA 2007). *** Criteria for the Merrimack River in October and November 2009 based on pH, temperature and salmonid species life­stage dependency. Results and Discussion Ammonia Ammonia concentrations in Section 4 averaged 0.2 mg/L at the six sites tested in October. The highest concentrations were found at stations 47.3 (Tyngsborough Bridge) and 41.1 (Pawtucket Dam). The water quality limit for ammonia in October ranged from 4.59 mg/L to 7.03 mg/L, well above all of the ammonia levels measured. Likewise, ammonia concentrations measured in November averaged 0.004 mg/L and were lower than calculated limits of 0.36 mg/L to 5.70 mg/L. Ammonia was not detected with the Hach test strips, which have a minimum detection level of 0.25 mg/L, in Section 2 of the Merrimack River in September.
39 Nitrogen The nitrogenous compounds ammonia, TKN, and nitrate were sampled in Section 4 in October 2009. TKN levels averaged 0.43 mg/L, approximately one­third of the 1.24 mg/L LRWWU historical average. Highest concentrations were found at stations 47.3 (Tyngsborough Bridge) and 41.1 (Pawtucket Dam). Nitrate levels averaged 0.34 mg/L, greater than the unofficial action level of 0.31 mg/L used by the Charles River Watershed Association. Highest concentrations were found at station 49.6 (MA/NH border) and decreased going downstream, except for a slight increase at station 43.4 (Stony Brook). Criteria were exceeded at stations 49.6 (MA/NH border), 47.3 (Tyngsborough Bridge), and 46.4 (Lawrence Brook). Historical averages from LRWWU were also greater than CRWA criteria at 1.07 mg/L. Phosphorus Phosphorus was not detected during the screening in October in Section 4, the only time it was sampled in 2009. Detergents The Hach surfactant test kit provided by EPA was found to be most useful for testing discharge from pipes and small tributaries. Under most circumstances, detergents in the river mainstem would be too dilute for the kit to detect. However, the Hach test kit did detect detergents at station 19.1 near the Little River in September. The kit was also extremely helpful at two suspected hotspots as it provided immediate positive surfactant results of 0.5 and 0.75 ppm for a pipe discharge at the Abe Bashara boathouse in Lawrence and one into the Powwow River in Amesbury, respectively. Bacteria results received several weeks later of 8,130 cfu/100 ml in Lawrence and 41,060 cfu/100 ml in Amesbury confirmed the suspected problems at these sites. Metals Metals screening in Section 4 of the Merrimack River revealed the presence of aluminum, iron, and zinc, whereas arsenic, cadmium, chromium, copper, lead, and nickel were not detected. The Merrimack River is listed as impaired by New Hampshire Department of Environmental Services for aluminum in Nashua, Manchester, Hooksett, and Concord, and it is used as a coagulant by many waste water treatment facilities. The average concentration of aluminum collected in Section 4 was 0.10 ± 0.01 mg/L, which was consistent with results observed by LRWWU between 2002 and 2009, but over the chronic exposure limit of 0.087 mg/L set by EPA. Slightly higher than average aluminum concentrations were found at stations 47.3 (Tyngsborough Bridge), 46.4 (Lawrence Brook), and 42.4 (Rourke Bridge). Iron and zinc were also detected in the Merrimack, though at levels below the EPA limits of 1.00 mg/L and 0.120 mg/L, respectively. Average iron levels were 0.30 ± 0.02 mg/L, with the highest amounts found at the same three stations listed for aluminum
40 above. Zinc was detected at levels of 0.02 mg/L at stations 47.3 (Tyngsborough Bridge) and 41.1 (Pawtucket Dam). 0.12 Concentration (mg/L) 0.10 Freshwater chronic limit 0.08 0.06 0.04 0.02 0.00 49.6 47.3 46.4 44.6 43.4 42.4 41.1 Station Figure 15. Aluminum levels in Section 4 (Tyngsborough – Lowell) of the Merrimack River in Massachusetts on October 20, 2009. Red line indicates the EPA chronic exposure limit for aluminum in surface waters. Appendix B contains additional site­specific data for both nutrients and metals. While the data collected in 2009 is insufficient for drawing conclusions about nutrient and metals levels in the Merrimack River, the results will be used to guide MRWC’s 2010 Search and Restore Project monitoring. For example, some of the highest levels each of nitrate, TKN, ammonia, aluminum and iron were found at station 47.3 at the Tyngsborough Bridge. Just upstream, the sample from station 49.6 at the state border showed the highest level of nitrate collected in the section that day. Similarly, downstream at station 41.1 (Pawtucket Dam) water quality analysis showed the highest level of TKN and tied for the highest level of ammonia collected that day. MRWC will target these stations at the state border, the Tyngsborough Bridge, the Rourke Bridge (for high aluminum) and the Pawtucket Dam for future monitoring.
41 Pharmaceutical Product Screening Methods and Project Location MRWC had the opportunity in June of 2009 to conduct a single screening for pharmaceutical products in the Merrimack River. Our assumption was that because the river is the recipient of the discharge water from over 10 waste water treatment facilities and waste water is not treated to remove pharmaceuticals or personal care products, it was very likely that these substances would be present in the water. For the screening study, we chose to collect samples in Section 2 of the river in Massachusetts. Section 2 is just downstream from an area used by four municipalities for drinking water withdrawals and contains within it two major wastewater treatment facilities as well two large tributaries known for chronically high bacteria levels. Figure 16 shows the locations of the seven sampling locations: a Merrimack River baseline sample below the Essex Dam, one sample each at the Spicket and Shawsheen Rivers, and two samples each at the GLSD and Haverhill treatment plants. Tributary samples were collected where the tributaries and the Merrimack River meet and therefore contain a mix of waters from both sources. At the wastewater treatment facilities, one sample was collected upstream of the facility’s main discharge location and one sample was collected downstream of the pipe. Figure 16. Location of pharmaceutical sampling sites on the Merrimack River, June 24, 2009.
42 Water samples were collected using sterile sample containers provided by the laboratory by MRWC staff wearing protective gloves. No preservation additives or techniques were required. Samples were mailed overnight the same day to the laboratory in packaging designed to protect the sample containers. The lab analyzed the samples for 20 common pharmaceutical products listed in Figure 17. Pharmaceutical Screening Results and Discussion The screening clearly demonstrated that pharmaceutical and other drug products are present in the Merrimack River. As shown in Figure 17, the most commonly found substances were Carbamezapine (antidepressant), Diphenyhydramine (antihistamine) and Tramadol (pain reliever). Some substances, including some that would be expected in wastewater effluent, were not found at all, including Amphetamine, Cimetidine, Clotrimazole and Codeine. Am phetam ine Atenolol Azythromycin Carbam ezapine Chlorpheniram ine Cimetidine Clotrimazole Cocaine Codeine Dextromethorphan Diphenyhydram ine Erythromycin Metoprolol Miconazole Propranolol Ranitidine Terbinafine Tramadol Trimethoprime Tripolidine 0 1 2 3 4 5 Number of Sites Present 6 7 Figure 17. Pharmaceutical products found in Section 2 of the Merrimack River, June 24, 2009. Figure 18 illustrates that the site with the greatest number of substances present in the sample was the one furthest upstream just below the Essex Dam in Lawrence. Water at this site contains effluent from the LRWWU facility, and the tributaries between the Lowell treatment plant and the dam are relatively minor, providing only small amounts of diluting water. Of concern is the fact that this same stretch of water between Lowell and
43 Lawrence is used as the drinking water source for the municipalities of Andover (through water pumped into Haggetts Pond from the Merrimack), Lawrence, Methuen and Tewksbury. The sites with the least number of substances found were at the mouths of the Spicket and Shawsheen River. At these locations, just a mile downstream of the Essex Dam, where tributary and mainstem waters mix, relatively few drug compounds were found. This result suggests that the Spicket and Shawsheen Rivers, neither of which receives discharge from a wastewater treatment plant, are not significant sources for pharmaceutical contamination. At the wastewater treatment facilities, only the GLSD site exhibited the expected behavior of showing a greater number of pharmaceutical products downstream of the outfall pipe than upstream of it. All of the substances found in the upstream sample were also found in the downstream sample, with three additional substances, presumably coming from the treatment plant discharge pipe, also present. In contrast, the samples collected around the Haverhill WWTP discharge pipe showed the same number of compounds, most of which were the same in each location. However, one substance that was found in the upstream sample was not found downstream, and a different substance was found in the downstream sample that was not present upstream. 16 14 Upstream 12 Downstream 10 8 6 4 2 0 Essex Dam Spicket River Shawsheen River Greater Lawrence WWTP Haverhill WWTP Figure 18. Number of pharmaceutical products found at each site Section 2 of the Merrimack River, June 24, 2009.
44 Accomplishments and Next Steps MRWC’s goal for its water quality monitoring program is to collect regular, consistent baseline data on the mainstem of the Merrimack River in Massachusetts and New Hampshire, determine if nutrients, metals and pharmaceutical products are present in the river in dangerous amounts, and identify sources of contamination. Other studies and data collection efforts have successfully quantified the health of the river at a single point in time or have an extensive set of time series of data at a single point on the river, but prior to 2007, no long­term, monthly or weekly monitoring had been conducted over the entire length of the mainstem in Massachusetts in over a decade. To this end, MRWC has successfully re­engaged its Volunteer Environmental Monitoring Network to collect this important information in both Massachusetts and New Hampshire. Accomplishments As in past years, MRWC has collected consistent baseline water quality data over the course of six months in the Merrimack River. In 2009 we monitored regularly at 32 Massachusetts stations, expanded the program to seven New Hampshire stations, added two new stations in Section 3 in Massachusetts, and conducted continuous monitoring in the dam impoundment in Section 4. In addition, MRWC has also begun quantifying nutrient and metals contamination as part of the Merrimack River Search and Restore Project (formerly known as the Impairment Quantification Project) and conducted a screening for pharmaceutical products as part of the Merrimack River Safe Drinking Water Project. Last, MRWC conducted its first water quality monitoring trip via paddleboard in 2009, likely the first monitoring effort ever in New England to utilize this type of water vessel! In general, 2009 results confirm MRWC’s 2007 and 2008 monitoring season conclusions: the Merrimack River usually meets state water quality standards for Class B and Class SB rivers during dry weather, and increasingly often during wet weather. Fewer CSOs from the Lowell Regional Wastewater Treatment facility and the Greater Lawrence Sanitary District have reduced the number of extremely high bacteria levels found in the river, making the river safer for boating and swimming. Sewer overflows still occur during major rain storms but moderate storms are now less likely to cause major water quality impacts. Overall, except for a couple of chronic problem sites, the river is safe for both boating and swimming as long as there has been no significant local or upstream rainfall during the prior three days. At the conclusion of the second year of monitoring, MRWC outlined several tasks to follow up on the information gathered or the additional information still needed to determine the amount, nature and sources of pollution to the Merrimack River. Below is a description of how we addressed these tasks:
· Low pH – MRWC measured a few low pH values in 2008, but many more in 2009. The extremely low results found most recently resulted in follow­up monitoring by both MRWC and EPA, the production of a Merrimack River pH
45 memorandum sent to federal, state and local authorities, and an addition to the tools brought along on each monitoring trip. In the future, monitoring teams will have pH test strips and/or sample bottles to collect water samples for verification of water quality meter pH readings. MRWC will also immediately notify EPA of any extremely low values.
· High conductivity/TDS/salinity at site 26.9 – In 2009 MRWC added a monitoring station at the Shawsheen River and noted that conductivity, TDS and salinity tended to be higher in both the Shawsheen and Spicket tributaries than in the Merrimack mainstem. While conductivity and its related parameters at station 26.9 were consistent with downstream values in 2009, it is possible that prior year variable readings were influenced by the tributaries just a mile upstream as well as from treatment plant discharge.
· Bacteria contamination in the Spicket and Shawsheen Rivers – 2009 bacteria data, supported by a geometric mean of results over the Massachusetts state water quality limit, suggests that both the Spicket and Shawsheen Rivers frequently contain high levels of bacteria. Sampling along the length the tributaries will be necessary to pinpoint specific sources.
· Low dissolved oxygen in impounded areas ­ MRWC installed a water quality meter above the Pawtucket dam to collect continuous dissolved oxygen and other data over the course of two weeks. Results indicated that while high flows in the Merrimack maintained adequate DO in the water throughout the day during 2009, DO levels during the low flow summer season in 2007 probably dropped below standards based calculations using data collected mid­morning in 2007 and continuously in 2009.
· Hotspot monitoring in Section 4 – Bacteria data collected in 2008 indicated several potential hotspots in Section 4, especially around Stony Brook and between the Tyngsborough Bridge and Lawrence Brook. Because MRWC did not detect significant bacteria pollution in Section 4 in 2009, we were not able to trace any hotspots. Should future monitoring uncover similar results in this area, hotspot monitoring will be scheduled.
· Conductivity in section 4 – While Section 4 exhibited the greatest range of fresh water specific conductance, total dissolved solids and salinity values in 2008, it exhibited the most limited range of results for these parameters in 2009. Monitoring at the southern­most stations in Section 5 confirmed results gathered in Section 4 during 2009, though a greater range in conductivity and related parameter readings was found further upstream in Section 5, likely due to the influence of a major tributary and the Nashua wastewater treatment facility.
· Sources of bacteria pollution in New Hampshire – Elevated bacteria levels near Limit Brook in 2007 did not appear to be coming from the tributary according to hotspot samples collected in the brook in 2008. The 2009 monitoring program addressed this question by extending monitoring into southern New Hampshire. While no 2009 bacteria samples collected upstream of Limit Brook exceeded
46 Massachusetts state standards, additional monitoring will be conducted in 2010 to better characterize this area. MRWC accomplished several other tasks as part of the Merrimack River Monitoring Program during 2009, including the elimination of a pollution source, the first year tasks associated with the Search and Restore Project and the initiation of the Safe Drinking Water Project:
· Septic leak in Lawrence fixed – MRWC identified a pipe discharging polluted effluent into the Merrimack River near the Abe Bashara boathouse, home of Greater Lawrence Community Boating, in Lawrence. By working with MA DEP officials in cooperation with the city, the source of the leaking septic system was determined and the leak fixed, protecting the underprivileged children boating and swimming in the area.
· Pharmaceutical products found in river – The Safe Drinking Water Project screening for pharmaceutical products in Section 2 proved that drugs are present in the Merrimack in areas where the river is used as a source of drinking water. While studies are on­going to determine what levels of various pharmaceutical products are inimical to human and wildlife health, their presence in the river makes this area of research an important one for Merrimack Valley residents.
· Merrimack River nutrient and metals monitoring begun – Nutrient and metals monitoring began in 2009 as part of the Search and Restore Project. Results collected in 2009 have provided baseline nutrient data for the river and identified critical stations to target for the wet­ and dry­weather monitoring planned for 2010. Analysis of metals in the water has also identified aluminum as a potential element of concern. Next Steps The Baseline Water Quality Monitoring Project has successfully completed its third year, and has spun off several additional projects designed to investigate Merrimack River water quality concerns in greater detail. While the Baseline Project will continue to function at the core of these newer project, MRWC expects the focus of its monitoring will now shift to target critical areas and additional pollutants. For the 2010 monitoring season, MRWC plans to focus on the following items:
· Increased baseline monitoring in Section 5 – MRWC plans to incorporate Section 5 fully into its Baseline Monitoring Project in 2010. We have already received funding from the New Hampshire Charitable Foundation to support Nashua area monitoring, and EPA has agreed to provide bacteria sample analysis for Sections 1 through 5 in 2010.
47 · Low pH monitoring – MRWC will continue to monitor pH throughout the Merrimack River in Massachusetts and southern New Hampshire to attempt to better identify trends in pH and the cause of the low values found in 2008 and 2009. Inclusion of pH test strips and extra sample bottles with monitoring equipment will allow for verification of results when low pH values are found.
· Bacteria hotspot follow­up monitoring – Of the several major bacteria pollution sources MRWC has discovered during the past three years, only two have been reported as fixed. MRWC will continue to monitor identified problem sites and work with federal, state and local authorities until these pollution sources have been definitively eliminated.
· Dry­ and wet­weather nutrient monitoring – With support from the Massachusetts Environmental Trust, MRWC will begin the second year of its Search and Restore Project (formerly known as the Impairment Quantification Project). This project will collect four sets of nutrient and bacteria samples, two sets during wet weather and two sets during dry weather, at 20 mainstem monitoring stations in Massachusetts.
· Intensive bacteria monitoring – Assuming adequate funding is received, MRWC will initiate the Merrimack River Safe Beaches Project in 2010. This project will collect bacteria and nutrient data three to five times per week at two or four (depending on funding levels) popular swimming and boating locations during the summer recreational season. This data will be posted at the beaches and on our website within 24 hours of data collection, letting the public know whether or not it is safe to swim or boat in the river. The Merrimack River Monitoring Program has successfully established current baseline water quality information in the Merrimack River, identified and assisted with correcting several pollution hotspots, conducted a pharmaceutical product screening proving the presence of 16 drugs in the river, and begun monitoring for nutrients. MRWC has also effectively engaged local community organizations and citizens in protecting the river and spreading information about the work that yet needs to be done to achieve MRWC’s vision of a pure Merrimack River, respected and enjoyed.
48
References Charles River Watershed Association. 2009. [Online] Charles River Monthly Monitoring Program 2007 Year­End Report. Charles River Watershed Association: Weston, MA. http://www.crwa.org/water_quality/monthly/2007/IM3_2007_FINAL.pdf City of Haverhill Water/Wastewater Division. 2010. Combined Sewer Overflow Annual Report 2009. City of Haverhill Water/Wastewater Division: Haverhill, MA. (Data used in this report was obtained directly from Paul J. Jessel, Collection System Supervisor, but will be posted online at: http://www.ci.haverhill.ma.us/ departments/water/waste_water/collection/) Lowell Regional Wastewater Utility. 2010. 2009 Diversion Summary Report. Lowell Regional Wastewater Utility: Lowell, MA. (Data used in this report was obtained directly from Brandon Kelly, Staff Engineer, but will be posted online at: http://www.lowellma.gov/depts/wastewater/cso/. Precipitation data was obtained by LRWWU from the University of Massachusetts­Lowell Weather Center.) Massachusetts Department of Environmental Protection. 2007. Massachusetts Surface Water Quality Standards (Revision of 314 CMR 4.00). Massachusetts Department of Environmental Protection, Division of Water Pollution Control, Technical Services Branch: Westborough, MA. http://www.mass.gov/dep/service/regulations/314cmr04.pdf Meek, James. 17 November 2009. Environmental Analyst, Massachusetts Department of Environmental Protection, Division of Watershed Management. Personal communication. New Hampshire. 1998. [Online] New Hampshire Title L Water Management and Protection, Chapter 485­A Water Pollution and Waste Disposal, Classification of Waters, Section 485­A:8. New Hampshire: Concord, NH. http://www.gencourt.state.nh.us/rsa/html/L/485­A/485­A­8.htm NOAA. Undated. [Online] SOD – Daily Surface Data. National Oceanic and Atmospheric Administration, National Climatic Data Center: Asheville, NC. Accessed 25 March 2009. http://www.ncdc.noaa.gov/oa/climate/stationlocator.html Parker, G.W. 2006. Time of travel and dispersion in the Merrimack River in Massachusetts from the state line to the Atlantic Ocean. United States Geological Survey Scientific Investigations Report 2006­5103: Reston, VA. 28 p.
49 United States Environmental Protection Agency. 2009. [Online] National Recommended Water Quality Criteria. Accessed 11 March 2010. http://www.epa.gov/waterscience/criteria/wqctable/index.html United States Environmental Protection Agency. 2007. [Online] 2007 Updated Aquatic Life Copper Criteria. http://www.epa.gov/waterscience/criteria/copper/2007/index.htm. United States Geological Survey. Undated. [Online] USGS Surface­Water Daily Data for the Nation. United States Geological Survey: Reston, VA. Accessed 13 April 2010. http://waterdata.usgs.gov/nwis/dv?referred_module=sw&site_no=01100000
50 Appendix A: Summary of Bacteria Results 2007 – 2009
51 2007 – 2009 Bacteria Summary 2009 2008 2007 Weather Dry Wet Dry Wet Dry Wet State Single Sample Swim Boat 96 99 95 100 95 94 74 100 98 100 63 79 NH Standards Swim Boat 85 99 68 98 90 100 43 81 95 97 46 62 State ­ Sw im CRWA Standards Swim Boat 74 99 61 98 90 100 53 82 97 100 62 71 State ­ Boat 100 100 2007 90 2007 90 2008 2009 80 2008 2009 80 70 70 60 60 50 50 40 40 Dry Wet Dry NH ­ Sw im Wet NH ­ Boat 100 100 2007 90 2007 90 2008 2009 80 2008 2009 80 70 70 60 60 50 50 40 40 Dry Wet Dry CRWA ­ Sw im Wet CRWA ­ Boat 100 100 2007 90 2007 90 2008 2009 80 2008 2009
80 70 70 60 60 50 50 40 40 Dry Wet Dry Wet 52 Appendix B: Water Quality Tables
53 Bacteria Results Section Station 1 2 3 4 5 2.7 4.4 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.2 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 Test May Enterococcus Enterococcus Enterococcus Enterococcus Enterococcus Enterococcus Enterococcus Enterococcus E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli E. Coli ND 20 ND 10 8* 31 ND 41 ND 52 10 140* 10 118 10 52 June July 16 25 21 16 16 25 39 195 61 31 41 41 75 30 121 98 81* 93 85 96 92 384 913 68 44 34 21 16 72* 75 39 30* 10 10 52 52 84 121 141* 54 85 129 98 45* 58 245 80 30 30 69 160 96 75* 86 91 30 64 25* 30 30 25 21 12 16 6* 8 54 12 8 4 34 16 8 19* 30 4 34 12 4 16 August September October 53* 10 41 ND 41 41 63 41 53 80 54* 70 64 91 122 384 54 30 85 70 137* 195 131 159 142 325 34 12 39 25* 25 43 16 25 30 25 10 ND ND 10 ND ND 20 26* 39 44 1,580 39 54 53 142* 58 85 145 175 175* 52 158 132 161 122 182* 202 198 208 406 445 205 120 233 34 70 68 32* 30 54 34 4 4 23* 30 16 24 12 30 200 25 21 8 4 37* 25 8 30 49 23* Geometric Mean 33 16 22 20 29 42 51 53 72 87 183 86 90 103 202 181 74 29 51 51 43 56 58 65 25 12 13 22 18 22 12 16 Wet weather event (>= 0.25 in. precip over prior 72 hours) * Average of station samples Bacteria concentrations in number of colony forming units per 100 milliliters (cfu/100 mL) collected in the Merrimack River, Massachusetts and New Hampshire during 2009. Analysis performed at EPA Region I laboratory in North Chelmsford, Massachusetts.
54 Water Temperature Results Section Station 5/12 5/14 5/20 5/27 5/30 6/10 6/11 6/24 7/13 7/14 7/22 7/23 7/28 1 2 3 4 5 2.7 4.4 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 51.8 52.5 53.1 54.4 55.9 15.3 16.6 16.9 16.9 17.0 16.5 16.3 15.8 15.6 15.4 15.4 15.6 15.6 15.4 15.4 15.7 15.6 15.6 15.5 15.4 15.3 15.3 15.3 15.5 19.2 19.2 19.0 19.0 19.1 19.4 19.5 19.3 18.3 18.3 18.3 18.3 18.3 18.3 18.3 18.3 17.8 18.3 18.3 18.3 18.3 18.3 17.3 17.5 18.3 16.6 16.6 16.5 16.5 16.7 16.9 16.8 19.1 22.8 22.9 22.8 22.8 22.8 22.8 22.7 22.4 22.5 22.5 22.6 22.5 22.5 20.5 22.5 22.5 22.5 22.3 22.4 22.4 22.4 22.5 22.4 19.2 19.4 19.3 19.2 19.1 19.2 19.2 19.9 19.8 19.7 19.7 19.7 19.6 19.3 19.2 18.3 8/1 22.3 22.3 22.3 22.2 22.3 22.3 22.3 22.2 23.3 23.3 23.3 23.2 23.1 23.0 21.3 21.4 21.4 21.4 21.2 21.2 21.1 21.1 18.2 21.0 21.1 20.9 20.9 20.9 20.8 21.2 Median water temperature in degrees Celsius (°C) by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
55 Water Temperature Results (continued) Section Station 8/11 8/12 8/13 8/19 8/20 8/26 9/8 1 2 3 4 5 2.7 4.4 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 51.8 52.5 53.1 54.4 55.9 23.5 23.6 23.6 23.5 23.3 23.3 23.0 22.8 17.0 25.0 26.5 26.7 26.8 26.8 26.5 26.1 26.6 26.6 26.4 26.3 26.1 25.9 25.7 25.7 9/9 9/16 9/23 10/10 10/14 10/20 10/27 10/28 20.6 21.0 20.7 20.6 20.9 21.2 21.1 21.1 25.5 25.5 25.7 25.9 26.2 26.0 24.7 26.5 26.3 18.6 18.7 18.8 18.9 18.9 18.7 18.5 18.6 14.9 15.0 15.0 14.9 14.9 14.8 11.5 11.9 12.4 12.2 12.5 12.2 12.0 12.0 9.1 9.0 9.0 9.0 8.9 8.9 8.8 19.3 19.1 18.7 19.0 18.9 19.4 17.5 19.8 19.9 9.3 9.3 9.3 9.2 9.2 9.1 10.2 9.7 9.0 23.4 23.2 23.1 23.2 23.0 23.2 23.1 23.3 23.2 22.3 22.3 22.4 22.4 22.4 22.4 22.5 22.4 22.4 22.4 25.7 20.8 20.5 20.4 20.2 20.4 20.5 20.5 20.4 20.3 20.3 8.4 8.1 8.1 8.2 8.3 8.3 8.3 8.3 8.3 8.3 Median water temperature in degrees Celsius (°C) by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
56 Dissolved Oxygen Results Section Station 5/12 5/14 5/20 5/27 5/30 6/10 6/11 6/24 7/13 7/14 7/22 1 2 3 4 5 2.7 4.4 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 51.8 52.5 53.1 54.4 55.9 9.0 9.7 9.6 10.0 10.3 10.2 9.3 11.1 11.2 11.6 12.1 11.7 11.6 11.7 9.6 9.4 9.4 9.3 9.3 9.3 9.3 9.4 9.3 10.0 8.7 8.5 8.4 8.5 8.8 8.8 9.0 7.8 8.3 8.0 8.1 8.2 8.4 8.7 9.7 9.2 9.3 9.5 9.7 9.3 9.7 9.3 9.3 9.6 10.5 8.5 8.2 7.8 7.7 7.8 7.6 8.8 7/28 8/1 8.8 8.7 8.8 8.6 8.8 8.8 8.8 9.0 8.6 8.3 8.2 8.0 7.8 7.5 8.8 7.8 7.9 7.6 7.6 7.5 7.5 7.9 7.7 8.5 8.5 8.5 8.3 8.1 8.7 8.6 9.4 8.4 8.2 8.0 7.8 7.8 7.7 7.7 7/23 8.7 8.0 8.1 7.9 7.8 7.7 7.8 7.9 9.9 10.0 10.0 10.0 10.1 10.2 8.8 8.8 8.8 8.8 8.8 8.8 8.7 8.8 9.8 8.3 8.4 8.7 8.6 8.6 8.6 8.9 Median dissolved oxygen in milligrams per liter (mg/L) by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
57 Dissolved Oxygen Results (continued) Section Station 8/11 8/12 8/13 8/19 8/20 8/26 9/8 1 2 3 4 5 2.7 4.4 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 51.8 52.5 53.1 54.4 55.9 8.3 8.5 8.4 8.4 8.3 8.4 8.1 8.1 8.9 8.1 8.2 8.4 9.0 8.3 8.0 8.2 6.0 6.2 6.6 6.2 6.2 6.2 6.2 7.1 9/9 9/16 9/23 10/10 10/14 10/20 10/27 10/28 8.4 8.6 8.2 8.3 8.6 8.7 8.6 8.3 7.4 7.4 7.7 8.0 8.0 8.2 6.9 8.3 8.2 9.0 9.1 9.2 9.2 9.1 8.7 8.7 9.2 9.7 9.9 10.3 10.2 10.3 10.1 10.2 10.4 11.0 10.6 10.6 10.6 10.6 10.8 8.8 8.4 8.3 8.7 8.5 9.1 9.6 9.3 9.3 8.7 9.4 9.9 8.0 7.8 7.8 7.7 8.0 7.9 7.9 7.2 7.7 8.4 8.4 8.5 8.3 8.4 8.3 8.5 8.3 8.4 8.3 7.9 8.0 8.0 8.0 8.0 8.2 8.2 8.3 8.0 8.0 8.2 11.9 11.6 11.6 11.3 11.3 Median dissolved oxygen in milligrams per liter (mg/L) by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
58 pH Results Section Station 5/12 5/14 5/20 5/27 5/30 6/10 6/11 6/24 7/13 7/14 7/22 7/23 7/28 1 2 3 4 5 2.7 4.4 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 51.8 52.5 53.1 54.4 55.9 7.0 6.4 6.3 6.3 6.3 5.3 3.3 6.5 6.4 6.4 6.5 6.5 6.4 6.2 6.1 6.2 6.2 6.2 6.2 6.2 6.2 6.3 6.3 6.8 6.7 6.7 6.7 6.7 6.7 6.7 6.8 6.6 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.3 6.5 6.5 6.5 6.5 6.5 6.7 6.7 6.4 4.8 6.0 6.1 4.1 4.6 4.3 5.8 7.7 6.6 6.8 6.5 6.5 6.5 6.5 6.1 6.5 6.5 6.5 6.5 6.5 6.5 6.7 6.6 6.4 6.3 6.4 6.4 6.4 6.4 6.4 6.3 6.6 6.7 6.6 6.6 6.5 6.7 6.6 6.4 6.4 6.4 6.5 6.4 6.4 6.4 6.4 6.0 8/1 6.7 6.6 7.0 6.9 7.0 6.9 6.9 6.8 4.2 5.6 4.6 5.5 6.0 6.0 6.0 6.1 6.1 6.2 6.2 6.2 6.1 6.0 6.0 6.3 6.3 6.0 6.3 6.5 6.2 6.2 Median pH by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
59 pH Results (continued) Section Station 8/11 8/12 8/13 8/19 8/20 8/26 9/8 1 2 3 4 5 2.7 4.4 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 51.8 52.5 53.1 54.4 55.9 6.6 6.6 6.6 6.6 6.6 6.6 6.5 6.4 7.5 7.2 6.8 7.3 7.0 6.9 6.8 6.6 6.8 6.8 6.8 6.8 6.7 6.7 6.7 6.4 9/9 9/16 9/23 10/10 10/14 10/20 10/27 10/28 6.9 6.7 6.6 6.6 6.7 6.7 6.7 6.6 6.4 6.4 6.6 6.7 6.8 6.8 6.8 7.0 6.8 6.6 6.5 6.4 6.5 6.4 6.2 6.1 6.1 6.4 6.4 6.4 6.4 6.4 6.3 7.5 7.4 6.7 6.6 6.6 6.5 6.5 6.4 5.8 5.6 5.5 5.4 5.5 5.4 5.8 6.4 6.3 6.4 6.4 6.4 6.6 6.3 6.6 6.5 5.9 6.1 5.9 6.0 6.0 6.0 6.3 6.4 6.0 6.5 6.6 6.5 6.6 6.7 6.7 6.6 6.7 6.7 6.7 6.8 6.7 6.8 3.3 6.3 6.3 6.3 6.3 6.4 6.4 6.3 6.3 6.4 6.4 6.0 5.9 5.8 5.9 6.0 5.9 5.9 5.9 5.9 5.9 Median pH by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
60 Specific Conductance Results Section Station 5/12 5/14 5/20 5/27 5/30 6/10 6/11 6/24 7/13 7/14 7/22 7/23 7/28 8/1 Data from stations 2.7 and 4.4 were too disparate to calculate meaningful specific conductance medians due to the influence of ocean water. 1 2 3 4 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 5 213 188 187 187 185 182 117 119 118 124 122 111 106 108 104 103 103 102 100 102 99 211 207 206 203 202 202 138 138 138 139 137 137 154 137 134 132 169 161 411 303 125 169 159 157 161 152 170 135 194 193 189 186 186 200 491 174 180 178 169 169 187 155 177 151 189 190 194 195 176 211 176 143 145 143 141 145 144 144 142 127 127 125 125 126 125 196 196 195 195 194 102 109 106 103 119 104 99 119 118 114 114 113 113 112 114 99 117 103 128 51.8 97 52.5 139 53.1 199 54.4 164 55.9 96 Median specific conductance in micro­Siemens per cm (μS/cm) by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
61 Specific Conductance Results (continued) Section Station 8/11 8/12 8/13 8/19 8/20 8/26 9/8 9/9 9/16 9/23 10/10 10/14 10/20 10/27 10/28 Data from stations 2.7 and 4.4 were too disparate to calculate meaningful specific conductance medians due to the influence of ocean water. 1 2 3 4 5 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 51.8 52.5 53.1 54.4 55.9 164 163 166 176 166 169 253 563 188 188 187 187 161 158 156 154 154 156 182 182 179 178 178 179 191 189 180 175 201 246 592 178 176 228 219 219 220 220 218 185 184 183 177 177 177 203 248 171 165 169 218 226 235 208 258 253 412 197 195 119 113 110 107 115 111 441 254 99 160 147 144 170 142 166 133 196 122 121 120 118 119 116 116 111 114 121 116 130 132 132 129 127 135 133 128 129 132 133 128 121 118 120 138 131 123 129 127 126 Median specific conductance in micro­Siemens per cm (μS/cm) by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
62 Total Dissolved Solids Results Section Station 5/12 5/14 5/20 5/27 5/30 6/10 6/11 6/24 7/13 7/14 7/22 7/23 7/28 8/1 Data from stations 2.7 and 4.4 were too disparate to calculate meaningful TDS medians due to the influence of ocean water. 1 2 3 4 5 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 51.8 52.5 53.1 54.4 55.9 0.14 0.12 0.12 0.12 0.12 0.12 0.08 0.08 0.08 0.08 0.08 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.06 0.07 0.14 0.13 0.13 0.13 0.13 0.13 0.09 0.09 0.09 0.09 0.09 0.09 0.10 0.09 0.09 0.09 0.11 0.11 0.27 0.20 0.08 0.11 0.10 0.10 0.10 0.10 0.11 0.09 0.13 0.13 0.12 0.12 0.12 0.13 0.32 0.11 0.12 0.12 0.11 0.11 0.12 0.10 0.12 0.10 0.12 0.12 0.13 0.13 0.12 0.14 0.11 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.08 0.08 0.08 0.08 0.08 0.08 0.13 0.13 0.13 0.13 0.13 0.07 0.07 0.07 0.07 0.08 0.07 0.06 0.08 0.08 0.07 0.07 0.07 0.07 0.07 0.07 0.06 0.08 0.08 0.06 0.09 0.13 0.11 0.06 Median total dissolved solids in grams per liter as NaCl (g/L) by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
63 Total Dissolved Solids Results (continued) Section Station 8/11 8/12 8/13 8/19 8/20 8/26 9/8 9/9 9/16 9/23 10/10 10/14 10/20 10/27 10/28 Data from stations 2.7 and 4.4 were too disparate to calculate meaningful TDS medians due to the influence of ocean water. 1 2 3 4 5 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 51.8 52.5 53.1 54.4 55.9 0.11 0.11 0.11 0.11 0.11 0.11 0.16 0.37 0.12 0.12 0.12 0.12 0.10 0.10 0.10 0.10 0.10 0.10 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.11 0.13 0.16 0.39 0.12 0.12 0.15 0.14 0.14 0.14 0.14 0.14 0.12 0.12 0.12 0.12 0.12 0.12 0.13 0.16 0.11 0.11 0.11 0.14 0.15 0.15 0.14 0.17 0.16 0.27 0.13 0.13 0.08 0.07 0.07 0.07 0.08 0.07 0.29 0.17 0.07 0.10 0.10 0.09 0.11 0.09 0.11 0.09 0.13 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.07 0.07 0.08 0.08 0.08 0.09 0.09 0.08 0.08 0.09 0.09 0.08 0.08 0.09 0.09 0.08 0.08 0.08 0.08 0.09 0.09 0.08 0.08 0.08 0.08 Median total dissolved solids in grams per liter as NaCl (g/L) by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
64 Salinity Results Section Station 5/12 5/14 5/20 5/27 5/30 6/10 6/11 6/24 7/13 7/14 7/22 7/23 7/28 1 2 3 4 2.7 4.4 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 0.05 0.05 0.05 0.05 0.05 0.05 0.07 0.07 0.07 0.07 0.07 0.07 48.9 0.05 0.07 49.6 0.05 0.07 0.10 0.09 0.09 0.09 0.09 0.09 0.06 0.06 0.06 0.06 0.06 0.05 0.05 49.9 50.9 5 8/1 Data from stations 2.7 and 4.4 were too disparate to calculate meaningful salinity medians due to the influence of ocean water. 0.10 0.10 0.10 0.10 0.10 0.10 0.06 0.06 0.06 0.06 0.06 0.06 0.07 0.06 0.06 0.06 0.08 0.08 0.20 0.15 0.06 0.08 0.08 0.07 0.08 0.07 0.08 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.09 0.24 0.08 0.08 0.08 0.08 0.08 0.09 0.07 0.08 0.07 0.09 0.09 0.09 0.09 0.08 0.10 0.08 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.06 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.06 51.8 0.04 52.5 0.07 53.1 0.10 54.4 0.08 55.9 0.04 Median salinity in parts per thousand (ppt) by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
65 Salinity Results (continued) Section Station 8/11 8/12 8/13 8/19 8/20 8/26 9/8 1 2 3 4 5 2.7 4.4 6.8 8.3 9.4 10.6 11.8 14.1 16.8 17.8 19.1 22.3 25.6 26.9 27.8 28.2 29.1 29.6 31.4 32.2 33.4 35.1 36.3 37.9 38.9 40.0 41.1 42.4 43.4 44.6 46.4 47.3 48.9 49.6 49.9 50.9 51.8 52.5 53.1 54.4 55.9 9/9 9/16 9/23 10/10 10/14 10/20 10/27 10/28 Data from stations 2.7 and 4.4 were too disparate to calculate meaningful salinity medians due to the influence of ocean water. 0.08 0.08 0.08 0.08 0.08 0.08 0.12 0.27 0.09 0.09 0.09 0.09 0.07 0.07 0.07 0.07 0.07 0.07 0.09 0.09 0.08 0.08 0.08 0.08 0.09 0.09 0.08 0.08 0.09 0.11 0.29 0.08 0.08 0.11 0.10 0.10 0.10 0.10 0.10 0.09 0.09 0.09 0.08 0.08 0.08 0.10 0.12 0.08 0.08 0.08 0.10 0.11 0.11 0.10 0.13 0.12 0.20 0.09 0.09 0.06 0.05 0.05 0.05 0.05 0.05 0.21 0.12 0.05 0.07 0.07 0.07 0.08 0.07 0.08 0.06 0.09 0.06 0.06 0.06 0.05 0.06 0.05 0.05 0.05 0.05 0.06 0.05 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.07 0.06 0.06 0.06 0.06 0.06 Median salinity in parts per thousand (ppt) by station in the Merrimack River, Massachusetts and New Hampshire during 2009.
66 Nutrient Results Section Station 2 4 2 4 16.8 19.0 25.6 27.8 28.2 41.1 42.4 43.4 44.6 47.3 49.6 16.8 19.0 25.6 27.8 28.2 41.1 42.4 43.4 44.6 47.3 49.6 41.1 42.4 43.4 44.6 46.4 47.3 49.6 41.1 42.4 43.4 44.6 47.3 49.6 Test Ammonia* Ammonia* Ammonia* Ammonia* Ammonia* Ammonia as N Ammonia as N Ammonia as N Ammonia as N Ammonia as N Ammonia as N Detergent** Detergent** Detergent** Detergent** Detergent** Kjeldahl Nitrogen as N Kjeldahl Nitrogen as N Kjeldahl Nitrogen as N Kjeldahl Nitrogen as N Kjeldahl Nitrogen as N Kjeldahl Nitrogen as N Nitrate as N Nitrate as N Nitrate as N Nitrate as N Nitrate as N Nitrate as N Nitrate as N Total Phosphorus Total Phosphorus Total Phosphorus Total Phosphorus Total Phosphorus Total Phosphorus 9/16 9/16 ND ND ND ND ND 0.3 0.2 0.2 0.2 0.3 0.2 ND 0­0.25 ND ND ND 0.6 0.4 0.3 0.4 0.5 0.4 0.17 0.26 0.29 0.24 0.33 0.37 0.41 ND ND ND ND ND ND * Analyzed with Hach ammonia test strips. ** Analyzed with a Hach detergent (alkylbenzene sulfonate) test kit. Nutrient results in milligrams per liter (mg/l) in the Merrimack River, Massachusetts during 2009.
67 Metals Results Section Station Parameter Concentration 4 4 4 4 4 41.1 42.4 43.4 44.6 46.4 47.3 49.6 41.1 42.4 43.4 44.6 46.4 47.3 49.6 41.1 42.4 43.4 44.6 46.4 47.3 49.6 41.1 42.4 43.4 44.6 46.4 47.3 49.6 41.1 42.4 43.4 44.6 46.4 47.3 49.6 Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum Arsenic Arsenic Arsenic Arsenic Arsenic Arsenic Arsenic Cadmium Cadmium Cadmium Cadmium Cadmium Cadmium Cadmium Chromium Chromium Chromium Chromium Chromium Chromium Chromium Copper Copper Copper Copper Copper Copper Copper 0.09 0.11 0.09 0.09 0.10 0.10 0.09 ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Section Station Parameter Concentration 4 4 4 4 41.1 42.4 43.4 44.6 46.4 47.3 49.6 41.1 42.4 43.4 44.6 46.4 47.3 49.6 41.1 42.4 43.4 44.6 46.4 47.3 49.6 41.1 42.4 43.4 44.6 46.4 47.3 49.6 Iron Iron Iron Iron Iron Iron Iron Lead Lead Lead Lead Lead Lead Lead Nickel Nickel Nickel Nickel Nickel Nickel Nickel Zinc Zinc Zinc Zinc Zinc Zinc Zinc 0.28 0.30 0.28 0.29 0.32 0.31 0.29 ND ND ND ND ND ND ND ND ND ND ND ND ND ND 0.02 ND ND ND ND 0.02 ND Metals concentrations in milligrams per liter (mg/l) in the Merrimack River, Massachusetts October 22, 2009.
68