Scientific Investigations Report 2007–5022
Scientific Investigations Report 2007–5022
By Marc J. Zimmerman and Kimberly W. Campo
This report and cover are available in PDF Format (2,862 KB)
The U.S. Geological Survey synthesized, reviewed, and assessed Massachusetts water-quality data for use in the development of either numerical nutrient criteria for rivers and streams or a science-based framework for interpreting narrative criterial for nutrients. Water-quality data collected from 65 Massachusetts locations were selected to represent a wide range, but not a statistical selection, of drainage basins and high-, intermediate-, and low-nutrient ecoregions. Additional sites were selected at some locations to provide data to compare open- and closed-canopy effects on periphyton chlorophyll a concentrations. Nutrient and chlorophyll a concentrations are the primary focus of this study. Data for turbidity, color, dissolved oxygen, specific conductance, pH, and measures of aquatic-plant density also were examined. Water-quality data were analyzed by categories of year, ecoregion, drainage-basin size, Massachusetts nutrient ecoregion, presence of upstream wastewater dischargers, and canopy openness. Graphs and statistical analyses were used to evaluate data.
The U.S. Environmental Protection Agency recommends the 25th-percentile value of a water-quality constituent as the numerical nutrient criterion when using all available data for the constituent. In this study of Massachusetts waters, the 25th percentiles of median values at all sampling stations were: total phosphorus, 0.019 milligram per liter (mg/L); total nitrogen, 0.44 (mg/L); and turbidity, 1.2 nephelometric turbidity units (NTU). When the data are sorted by the two USEPA nutrient ecoregions in Massachusetts (VIII and XIV), the new values are: for Ecoregion VIII, total phosphorus, 0.009 (mg/L); total nitrogen, 0.289 (mg/L); and turbidity, 1.7 NTU; for Ecoregion XIV, total phosphorus, 0.028 (mg/L); total nitrogen, 0.583 (mg/L); and turbidity, 3.1 NTU. For the three Massachusetts lake-based nutrient ecoregions, the values are: high-nutrient ecoregion, total phosphorus, 0.030 (mg/L); total nitrogen, 0.642 (mg/L); and turbidity, 1.5 NTU; intermediate-nutrient ecoregion, total phosphorus, 0.016 (mg/L); total nitrogen, 0.419 (mg/L); and turbidity, 1.1 NTU; and low-nutrient ecoregion, total phosphorus, 0.011 (mg/L); total nitrogen, 0.289 (mg/L); and turbidity, 0.7 NTU.
In general, median nutrient concentrations were found to be higher in the three following categories of analysis than in their complementary groups: sites in USEPA nutrient Ecoregion XIV, sites downstream from major National Pollutant Discharge Elimination System-permitted wastewater dischargers, and sites in the Massachusetts high-nutrient ecoregion. The largest drainage-basin size class had higher median nitrogen (total and dissolved) concentrations than the smallest, but total median phosphorus concentrations were not significantly different. Median chlorophyll a concentrations did not vary significantly among the categories analyzed. The effects of open and closed canopies on median chlorophyll a concentrations were greater within groups defined by the categories used in this study than between the groups; open-canopy sites generally had higher median chlorophyll a concentrations than closed-canopy sites. More than 40 percent of the sampling stations were located downstream from major wastewater dischargers, and these dischargers were disproportionately located in USEPA Ecoregion XIV and the Massachusetts high-nutrient ecoregion and thus may constitute the same effect on water quality.
A number of expected relations among parameters analyzed did not materialize. chlorophyll a did not correlate well with any other parameters. No strong relations among the categories and nutrient concentrations or canopy openness were apparent. The occurrence of antecedent flows exceeding mean annual discharges by 300 percent within 28 days of sample collection did not correlate with decreases in chlorophyll a concentrations that might have resulted from scouring associated with increasing velocities. No relation was apparent between a measure of stream slope (another surrogate for velocity) and nutrient or chlorophyll a concentrations.
The relatively small number of sites in some of the categories analyzed and the presence of wastewater-treatment facilities on many of the streams made it difficult to definitively interpret the effects of the different groups within descriptive categories. A long-term sampling program providing representative data from a wider variety of streams than were sampled for this study, could yield a more robust dataset for analysis.
Abstract
Introduction
Sampling Sites and Categories
Sampling-Site Selection
Sampling-Site Categories
Sample Collection and Water-Quality Analyses
Assessment of Data
Characterization of Water-Quality Data
Nutrients and Turbidity
Color
Field Parameters
Chlorophyll a Concentrations and Plant Densities
Categorical Descriptions of Data
U.S. Environmental Protection Agency Nutrient Ecoregions
Drainage-Basin Size
Massachusetts Nutrient Ecoregions
Effects of Dischargers on Water Quality
Canopy Openness
Relations Among Categorical Data
Correlations among Water-Quality Variables
Relations among Chlorophyll a, Nitrogen, Phosphorus, and Canopy Openness
Stream-Velocity Effects
Effect of Antecedent Flows
Effect of Slope
Summary and Conclusions
Acknowledgments
References Cited
1. Map of Massachusetts showing sampling sites, presence of upstream National Pollutant Discharge Elimination System permitted dischargers, U.S. Environmental Protection Agency ecoregions, and Massachusetts nutrient ecoregions
2–17. Graphs showing—
2. Distribution of median (A) total phosphorus, (B) total nitrogen, (C) total dissolved nitrogen, and (D) chlorophyll a concentrations at all sampling sites by year in Massachusetts
3. Distribution of median (A) total phosphorus, (B) total nitrogen, (C) total dissolved nitrogen, and (D) chlorophyll a concentrations at 12 sampling sites by year in Massachusetts
4. Distribution of median (A) total phosphorus, (B) total nitrogen, (C) total dissolved nitrogen, and (D) chlorophyll a concentrations at all sampling sites by ecoregion in Massachusetts
5. Distribution of median (A) total phosphorus, (B) total nitrogen, (C) total dissolved nitrogen, and (D) chlorophyll a concentrations at all sampling sites by Massachusetts nutrient ecoregion
6. Distribution of median (A) total phosphorus, (B) total nitrogen, (C) total dissolved nitrogen, and (D) chlorophyll a concentrations at all sampling sites by drainage-basin-size class in Massachusetts
7. Distribution of median (A) total phosphorus, (B) total nitrogen, (C) total dissolved nitrogen, and (D) chlorophyll a concentrations at all sampling sites by National Pollutant Discharge Elimination System discharger category in Massachusetts
8. Distribution of median periphyton chlorophyll a concentrations at (A) closed- and (B) open-canopy sampling sites by Massachusetts nutrient ecoregion
9. Distribution of median periphyton chlorophyll a concentrations at (A) closed- and (B) open-canopy sampling sites for U.S. Environmental Protection Agency ecoregions VIII and XIV in Massachusetts
10. Distribution of median periphyton chlorophyll a concentrations at (A) closed- and (B) open-canopy sampling sites by drainage-basin-size class in Massachusetts
11. Distribution of median periphyton chlorophyll a concentrations at (A) closed- and (B) open-canopy sampling sites by National Pollutant Discharge Elimination System discharger category in Massachusetts
12. Density of (A) filamentous periphyton, (B) periphyton film, (C) aquatic plants, (D) aquatic moss, and (E) periphyton floc as a function of median total phosphorus concentrations and the percentage of canopy openness at all sampling sites
13. Density of (A) filamentous periphyton, (B) periphyton film, (C) aquatic plants, (D) aquatic moss, and (E) periphyton floc as a function of median total nitrogen concentrations and the percentage of canopy openness at all sampling sites
14. Median (A) total phosphorus and (B) total nitrogen concentrations as a function of median chlorophyll a concentrations by Massachusetts nutrient ecoregion and National Pollutant Discharge Elimination System discharger category
15. Median (A, B) total phosphorus and (C, D) total nitrogen concentrations as a function of median chlorophyll a concentrations at (A, C) closed- and (B, D) open-canopy sites by Massachusetts nutrient ecoregion and National Pollutant Discharge Elimination System discharger category
16. Median (A) total phosphorus concentrations, (B) total nitrogen concentrations, and (C) ratio of total nitrogen to total phosphorus as a function of median chlorophyll a concentrations and percentage of canopy openness in Massachusetts
17. Median (A) total phosphorus, (B) total nitrogen, (C) total dissolved nitrogen, and (D) chlorophyll a concentrations at all sampling sites as a function of slope in Massachusetts.
1. U.S. Geological Survey water-quality stations, station identifiers, and ancillary information
2. Summary statistics for median values of all water-quality parameters measured at sampling stations
3. Annual median water-quality data at sites that were sampled in 2001, 2003, and 2004
4. Twenty-fifth-percentile values for total phosphorus and total nitrogen concentrations and turbidity measured in U.S. Environmental Protection Agency ecoregions compared to values measured in this study and in Massachusetts low-, intermediate-, and high-nutrient ecoregions
5. Median values of representative data for stations in this report
6. Correlation coefficients among major water-quality parameters and percentage of open canopy and drainage area
7. Correlation coefficients among water-quality parameters, percentage of open canopy, and drainage area based on Massachusetts nutrient ecoregions
8. Regression coefficients for chlorophyll a versus total phosphorus, total nitrogen, the ratio of total nitrogen to total phosphorus, and percentage of open canopy for all sites, closed-canopy sites, and open-canopy sites
Suggested citation: Zimmerman, M.J., and Campo, K.W., 2007, Assessment of data for use in the development of nutrient criteria for Massachusetts rivers and streams: U.S. Geological Survey Scientific Investigations Report 2007–5022, 44 p.
If you have Adobe® Acrobat® or Adobe®Acrobat® Reader® installed on your computer, you may view and print the PDF version of this report. Acrobat Reader, is a free download from Adobe Systems, Inc. Users with disabilities can view information concerning accessibility at access.Adobe.com.
Director
U.S. Geological Survey,
Massachusetts-Rhode Island Water Science Center
Massachusetts Office
U.S. Geological Survey
10 Bearfoot Road, Northborough, MA 01532
(508) 490-5000
or visit our Web site at
http://ma.water.usgs.gov
http://ma.water.usgs.gov
U.S. Department of the Interior |
U.S. Geological Survey
URL: https://pubs.usgs.gov/sir/2007/5022
Page Contact Information: USGS Publishing Network
Page Last Modified: : Thursday, 01-Dec-2016 19:45:08 EST
