Link to USGS home page.
Publications—Scientific Investigations Report

Prepared in cooperation with the New England Interstate Water Pollution Control Commission

Assessment of Total Nitrogen in the Upper Connecticut River Basin in New Hampshire, Vermont, and Massachusetts, December 2002–September 2005

By Jeffrey R. Deacon, Thor E. Smith, Craig M. Johnston, Richard B. Moore, Rebecca M. Weidman, and Laura J. Blake


U.S. Geological Survey Scientific Investigations Report 2006-5144


AVAILABLE ONLINE ONLY

The body of the report is available in PDF Format ( 19,804 KB)


Abstract

A study of total nitrogen concentrations and loads was conducted from December 2002 to September 2005 at 13 river sites in the upper Connecticut River Basin. Ten sites were selected to represent contributions of nitrogen from forested, agricultural, and urban land. Three sites were distributed spatially on the main stem of the Connecticut River to assess the cumulative total nitrogen loads. To further improve the understanding of the sources and concentrations and loads of total nitrogen in the upper Connecticut River Basin, ambient surface water-quality sampling was supplemented with sampling of effluent from 19 municipal and paper mill wastewater-treatment facilities.

Mean concentrations of total nitrogen ranged from 0.19 to 2.8 milligrams per liter (mg/L) at river sampling sites. Instantaneous mean loads of total nitrogen ranged from 162 to 58,300 pounds per day (lb/d). Estimated mean annual loads of total nitrogen ranged from 49,100 to 21.6 million pounds per year (lb/yr) with about 30 to 55 percent of the loads being transported during the spring. The estimated mean annual yields of total nitrogen ranged from 1,190 to 7,300 pounds per square mile per year (lb/mi2)/yr.

Mean concentrations of total nitrogen ranged from 4.4 to 30 mg/L at wastewater-treatment sampling sites. Instantaneous mean loads of total nitrogen from municipal wastewater-treatment facilities ranged from 36 to 1,780 lb/d. Instantaneous mean loads of total nitrogen from paper mill wastewater-treatment facilities ranged from 96 to 160 lb/d.

The median concentration of total nitrogen was 0.24 mg/L at forested sites, 0.48 mg/L at agricultural sites, 0.54 mg/L at urban sites, 0.48 mg/L at main-stem sites, and 14 mg/L at wastewater-treatment sites. Concentrations of total nitrogen at forested sites were significantly less than at all other site types (p<0.05). Concentrations of total nitrogen at agricultural, urban, and main stem sites were not significantly different among each other (p>0.05) but were significantly greater (p<0.05) than at forested sites and significantly less than concentrations at wastewater-treatment sites (p<0.05). Total nitrogen concentrations at wastewater-treatment sites were significantly different from all other site types (p<0.05).

Annual yields of total nitrogen ranged from 732 to 1,920 (lb/mi2)/yr at forested sites; 1,550 to 2,980 (lb/mi2)/yr at agricultural sites; 1,280 to 1,860 (lb/mi2)/yr at urban sites that were not directly affected by wastewater effluent; 7,090 to 7,770 (lb/mi2)/yr at an urban site directly affected by wastewater effluent; and 1,300 to 2,390 (lb/mi2)/yr at main-stem sites.

In this study, the mean annual load and yield of total nitrogen at the Connecticut River at Wells River, VT, was estimated at 4.47 million lb/yr and 1,690 (lb/mi2)/yr, respectively. The mean annual load and yield of total nitrogen at the Connecticut River at North Walpole, NH, was estimated at 9.60 million lb/yr and 1,750 (lb/mi2)/yr, respectively. The mean annual load and yield of total nitrogen leaving the upper Connecticut River Basin, as estimated at the Connecticut River at Thompsonville, CT, was 21.6 million lb/yr and 2,230 (lb/mi2)/yr, respectively.

TABLE OF CONTENTS

Abstract

Introduction

Purpose and Scope

Previous Studies

Description of the Study Area

Data Collection and Analysis

Site Selection

Sample Collection

Data Analysis

Characterization of Total Nitrogen at River Sampling Sites

Moose River at Victory, VT, Station 01134500

Passumpsic River at Passumpsic, VT, Station 01135500

Connecticut River at Wells River, VT, Station 01138500

Ayers Brook at Randolph, VT, Station 01142500

White River at West Hartford, VT, Station 01144000

Sugar River at West Claremont, NH, Station 01152500

Connecticut River at North Walpole, NH, Station 01154500

Otter River at Otter River, MA, Station 01163200

North River at Shattuckville, MA, Station 01169000

South River near Conway, MA, Station 01169900

Green River near Colrain, MA, Station 01170100

Mill River at Northhampton, MA, Station 01171500

Connecticut River at Thompsonville, CT, Station 01184000

Characterization of Total Nitrogen at Wastewater-Treatment Sampling Sites

Comparison of Total Nitrogen Concentrations and Yields Among Site Types

Summary and Conclusions

References Cited

Appendix A: Supplemental Data

A-1. Annual loads, yields, and confidence intervals for total nitrogen and total phosphorus for river sampling sites in the upper Connecticut River Basin in New Hampshire, Vermont, and Massachusetts.
A-2. Estimates of seasonal total nitrogen load for river sampling sites in the upper Connecticut River Basin in New Hampshire, Vermont, and Massachusetts.
A-3. Estimates of seasonal total phosphorus load for river sampling sites in the upper Connecticut River Basin in New Hampshire, Vermont, and Massachusetts.
A-4. Regression equations for estimates of total nitrogen load and total phosphorus load for river sampling sites in the upper Connecticut River Basin in New Hampshire, Vermont, and Massachusetts.

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 .


For further information, contact:

Keith W. Robinson, Director
U.S. Geological Survey
New Hampshire - Vermont Water Science Center
361 Commerce Way
Pembroke, NH 03275

dc_nh@usgs.gov

(603) 226-7807

or visit our Web site at: http://nh.water.usgs.gov



Accessibility FOIA Privacy Policies and Notices

Take Pride in America home page. FirstGov button U.S. Department of the Interior | U.S. Geological Survey
Persistent URL: http://pubs.water.usgs.gov/sir20065144
Page Contact Information: USGS Publishing Network
Page Last Modified: Thursday, 10-Jan-2013 17:40:37 EST