Nitrogen Pollution: from the Sources to the Sea

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1 Nitrogen Pollution: from the Sources to the Sea C. Driscoll, D. Whitall, J. Aber,, E. Boyer, M. Castro, C. Cronan,, C. Goodale, P. Groffman, C. Hopkinson,, K. Lambert, G. Lawrence, S. Ollinger

2 2. Power plant bills in Congress. S Clean Power Act S Clear Skies Act S. 588 Acid Rain Control Act Public Policy - Air Will NOx emissions reductions be adequate to reduce nitrogen deposition and episodic acidification in sensitive ecosystems? 1. Tailpipe emissions standards at the state and federal levels. EPA Tier 1 & 2 reductions State-based low emission vehicle programs.

3 Public Policy - Water Are there adequate funds, incentives and standards to promote nitrogen removal by treatment plants? EPA 305b report - identifies nutrients from municipal treatment plants and runoff as a source of impairment. EPA Gap Analysis - predicts a shortfall of $ million dollars for operating and capital improvements of publicly owned treatment plants. Water quality standards for total nitrogen do not exist. EPA developing criteria for states. Target for 2004 relaxed.

4 Federal Activity 1. Bills to fund water quality improvements play important role. S Water Quality Financing Act S Water Quality Investment Act S Water Quality Investment Act Includes grant program for nitrogen removal, Section 701. Reduction to 4 mg/l. 2. EPA progress on nutrient criteria would provide greater regulatory guidance.

5 Public Policy - Land Are there appropriate measures to ensure results (e.g. land taken out of production provides net reduction in nitrogen runoff)? Incentives for improved agricultural practices in the U.S. Farm Bill are important here, such as: Conservation Reserve Program EQIP Program

6 Outline Background Inputs of Nitrogen to the northeastern U.S. Effects of Nitrogen Pollution Management Options to Reduce Nitrogen Pollution

7 Major Sources 1.Power plant emissions 2.Vehicle emissions 3. Septic tank leakage 4. Manure/livestock runoff 5. Agricultural emissions 6.Fertilizer runoff (e.g. lawns and fields) 7. Wastewater effluent 8. Food and feed imports

8 Fertilizer Production NH 3 Feed Animal Nitrogen Cascade NH 3 Atmospheric Effects Atmospheric Deposition NH 3 NO 3 - NO x Energy Production Ozone Formation NO x NO 3 - N 2 to atm. Denitrification N 2 O Forest Effects Human Food Consumption NO - 3 NO 3 - NO 3 - Groundwater Effects NO 3 - NO 3 - Surface Water Effects NO 3 - Human Health/ Plant Damage Drinking water quality Greenhouse Effect Coastal Effects NO 3 - Adapted from Galloway and Cowling, 2002.

9 Study Area

10 Northeast Population and Land Use Trends Population (million) New York 10 5 New England Percent total land area 80% 60% Forest 40% Farmland 20% Other 0% A) U.S. Bureau of Census, 1996; B) USDA 1997, NASS 1999.

11 Critical Questions What are the major inputs of anthropogenic nitrogen? What are the ecological effects of nitrogen inputs? What management options are available to mitigate these effects?

12 Inputs of Anthropogenic Nitrogen Atmospheric deposition (ammonia, nitrate, dissolved organic N) Food imports Fertilizer inputs Feed imports Nitrogen fixation by leguminous crops

Atmospheric N Emissions 150 100 50 Legend thousand kt N/yr Mobile NO x Point Source NO x Area NO x Ag

13 Atmospheric N Emissions Legend thousand kt N/yr Mobile NO x Point Source NO x Area NO x Ag NH 3 Mobile NH 3 Other NH 3 Source area based on 21 hour back trajectory Driscoll et al In review.

14 Lynch and Grimm, Wet Nitrate Nitrogen Wet Deposition Wet Ammonium kg NO 3- ha -1 yr -1 kg NH 4 + ha -1 yr -1

15 Long Term Precipitation Chemistry At Hubbard Brook, NH

16 Watershed Inputs: In small remote forested watersheds, such as the Hubbard Brook Experimental Forest in New Hampshire, anthropogenic N inputs are typically dominated by atmospheric deposition. Large coastal watersheds have more diverse N sources.

17 Nitrogen in Food Daily Nitrogen Consumption New England and New York, Nitrogen (1000 kilograms) FATS & OILS FRUIT VEGETABLES LEGUMES OTHER DAIRY CHEESE LOWFAT MILK WHOLE MILK GRAIN EGGS FISH POULTRY MEAT Year

18 Application of N fertilizers to major USA crops % of cropland receiving N fertlizer Wheat Cotton Corn Soybeans Source: USDA National Agricultural Statistics Service

19 Anthropogenic N Inputs to Large, Developed Watersheds From Driscoll et al In review.

20 Fate of Nitrogen Inputs Denitrification Biomass storage Soil storage Groundwater storage Exported to estuaries Exported in food and feed From Howarth et. al, 2002.

21 Anthropogenic N Loading to Major Estuaries From Driscoll et al In review.

22 Second Question 1. What are the major inputs of anthropogenic nitrogen to the northeastern U.S.? 2. What are the ecological effects of nitrogen inputs? 3. What management options are available to mitigate these effects?

23 Environmental issues linked to N Ground-level ozone Acid rain and acidification of forests & streams Forest saturation Over-fertilization of coastal waters Haze & reduced visibility Groundwater contamination Climate change

24 Ground-level ozone

25 Ground-level Ozone Formation Ollinger1 HNO 3 OH NO 2 VOCs UV Sunlight OH O 2 RO 2 O 2 O NO RO O 3 Courtesy of Scott Ollinger.

26 Counties with 1 Hour Ozone Standard Non-attainment

27 Figure 6 Estimated Reduction in Forest Growth due to Ozone Estimated Reduction in Forest Growth due to Ozone NY, NY Danbury, CT Ware, MA Chelsea, MA Schenectady, NY Bennington, VT Manchester, NH Portsmouth, NH Syracuse, NY Cape Elizabeth, ME Lake Placid, NY Bangor, ME % Reduction in in NPP Growth From Driscoll et al In review. 58

28 Acid Rain/Forest N Saturation Loss of nitrate to surface waters Episodic acidification of streams Acidification effects on biota

29 From Aber et al In review. Nitrate Deposition vs. Streamwater Nitrate NO3 - (umol/l) Catskills Adirondacks Massachusetts Vermont New Hampshire Maine ANNUAL MEAN NO Estimated N Deposition (kg/ha-yr)

km 2 ) 40000 30000 20000 10000 0 3 4 5 6 7 8 9 10 11 12 N Deposition

30 36% of northeastern forest receives >8 kg N per hectare, per year. Histogram of N deposition for forested areas only # pixels (1 km 2 ) N Deposition (Kg/ha * yr) Note: areas with 8 kg/ha/yr or more tend to show high NO - 3 in stream water.

31 The Effects of Nutrient Over-Enrichment Coastal Eutrophication

The Problem: Symptoms and Consequences of Nutrient Enrichment Nutrient Inputs Primary Secondary Consequences Effects Effects of Symptoms Increased

32 The Problem: Symptoms and Consequences of Nutrient Enrichment Nutrient Inputs Primary Secondary Consequences Effects Effects of Symptoms Increased Nitrogen Load Increased Primary Production Loss of Habitat Low D.O. Algal Blooms Fish kills Human health risks Loss of Tourism Closed fishing areas

33 High Eutrophic Conditions High Eutrophic Conditions 44 estuaries exhibit high expression of eutrophic conditions From NOAA s National Estuarine Eutrophication Assessment, Bricker et al., 1999.

35 Eutrophication and DO

36 Eutrophication and HAB

37 Eutrophication and SAV

38 Length and Max. Area of Hypoxia in Long Island Sound Length of Hypoxic Event (days) Days Max. Area Maximum area of hypoxia (km 2 ) Courtesy of Connecticut Department of Environmental Protection

40 Increasing Occurrence of Harmful Algal Blooms (HAB)

41 Eutrophication of Seagrass Beds Pristine First stage of decline Epiphytes on blades Water column algal blooms

42 Which Nutrients Cause Eutrophication? Long-term changes in sewage N and P content in the Himmerfjarden estuary point to N as the critical nutrient.

43 Which Nutrients Cause Eutrophication? Experiments in estuarine mesocosms in Narragansett Bay showed nutrient limitation by N but not P.

44 Which Nutrients Cause Eutrophication? Major changes in marine biota occurred following P reductions in Laholm Bay, Sweden, indicating N to be the cause of eutrophication

45 Which Nutrients Cause Eutrophication? Low N:P ratios found in most estuaries at the time of peak primary production indicates N limitation. Triangles represents N:P during peak production.

46 Nitrogen Yield from MR Basin

47 Critical Questions 1. What are the major inputs of anthropogenic nitrogen to the northeastern U.S.? 2. What are the ecological effects of nitrogen inputs? 3. What management options are available to mitigate these effects?

PnET BGC (Biogeochemical) Model PnET Water balance

Deposition Dry Deposition Climatic data Solar

Mineralization Uptake Shallow water flow BGC

exchange Adsorption Humic binding Aluminum

48 PnET BGC (Biogeochemical) Model PnET Water balance Photosynthesis Living biomass Litterfall Wet Deposition Dry Deposition Climatic data Solar radiation Precipitation Temperature Net Mineralization Uptake Shallow water flow BGC Aqueous reactions Surface reactions Cation exchange Adsorption Humic binding Aluminum dissolution/precipitation Weathering Deep water flow BGC Surface water Aqueous reactions

49 Modeling Reduced N Inputs to Forested Watersheds Atmospheric deposition is the dominant source of anthropogenic nitrogen in remote forested watersheds. Management options: 1. 75% reduction in electric utility NO x from current levels % reduction in vehicle NO x (EPA Tier 2 regulations). 3. Aggressive vehicle reduction (90% for cars above Tier 2) 4. 34% reduction in agricultural NH 3 emissions by animal waste treatment. Also, run with a concurrent 75% reduction in S emissions

50 PnET Results from Biscuit Brook NO 3 - Deposition (g/m 2 -yr) Without SO 4 2- Controls With SO 4 2- Controls NH 4 + Deposition (g/m 2 -yr) 2 SO 4 - Deposition (wet & dry) (g/m 2 /yr) NO 3 - (µmol/l) CAAA + integrated controls CAAA + aggressive vehicle NOx CAAA + tier II CAAA + additional utility NOx CAAA SO 4 2- (µmol/l) Year

51 PnET Results from Biscuit Brook

52 Inputs N Fertilization N Fixation Atmospheric Deposition Livestock Waste Outputs Crop Harvest Animal Grazing Ammonia Volatilization Denitrification Agricultural Lands (Crops and Pastures) Watershed and Riverine Losses Soil Climate N Fertilization Land Cover Atmospheric Deposition SWAT NPS Runoff Above Fall Line N Inputs WATERSN MODEL Human Population Wastewater N Discharge Point and NPS Septic Systems Below Fall Line N Inputs Atmospheric Deposition Nitrogen Fixation Upland Forests Atmospheric N Deposition Nitrogen Inputs to Estuary

53 Modeling Reduced N loading to Estuaries N inputs to estuaries are characterized by multiple sources. Management options evaluated: 1. Reduced N emissions to atmosphere 75% reduction in utilities NO x EPA Tier 2 reductions in vehicle emissions 90% reduction above Tier 2 in NO x from cars 34% reduction in agriculture NH 3 2. Biological Nitrogen Removal (BNR) for WWTPs 3. Septic system improvements 4. Offshore pumping of waste 5. Agricultural Best Management Practices (33% reduction in runoff N).

54 33% ag WATERSN Results for Long Island Sound and Casco Bay Percent Reduction in N Loading % edge of field ag Basinwide BNR Mobile Tier II Vehicle Tier 2 Integrated Legend Long Island Sound Casco Bay Integrated scenario includes basinwide BNR + enhanced septic +aggressive mobile +aggressive utilities BNR is Biological N Removal in WWTP Driscoll et al In review.

55 Residual N for Long Island Sound and Casco Bay LIS Casco Bay ag runoff forest runoff forest runoff Urban runoff N deposition Urban runoff N deposition Human Waste Human Waste

56 Ecosystem Protection for minimizing N inputs and runoff Wetlands protection. Conservation of forested and non-urbanized areas. Farmland reserve programs to reduce fertilizer and waste inputs in sensitive lands.

57 Conclusions: Inputs Anthropogenic N inputs to upland forested watersheds are dominated by emissions and deposition (~95%). N inputs to large, developed watersheds are diverse and are dominated by food (38-75%), atmospheric deposition (11-36%) and fertilizer (11-32%). N to loading to downstream estuaries is dominated by wastewater inputs (36-81%). Atmospheric deposition (14-35%) and runoff from agricultural (4-20%) and urban lands (<1-20%)are also large.

58 Conclusions: Effects Ground-level N emissions play a primary role in formation of ground level ozone. 26 million people in the study region experience air quality that exceeds the public health standard for ozone. Ambient ozone is projected to reduce forest productivity in the NE from 4-16%. Acid rain Nitrate is an increasing component of the acidity in acid rain. 40% of lakes in the Adirondacks and 15% in New England are still chronic or seasonally acidic. Nitrate is the key contributor to acid episodes that release Al to streams.

59 Conclusions: Effects Forest N saturation 36% of forestland in the NE receive N deposition above levels which result in elevated nitrate leaching an early indication of saturation. Coastal over-fertilization 61% of the estuaries surveyed by NOAA show signs of over-fertilization. Over-fertilization has been shown to cause low-oxygen conditions, loss of habitat and algal blooms in some estuaries.

60 Conclusions: Management PnET Results - Emissions Nitrogen deposition <8 kg/ha-yr is achieved by all options beyond the 1990 CAAA by 2010 for Biscuit Brook and Hubbard Brook. The thresholds for ANC, ph and soil base saturation are not achieved under any N only control scenario. Policies that reduce N and S allow for these thresholds to be approached within 50 years. Seasonal reductions in N emissions may help with summertime ozone, but year-round controls are much more effective in mitigating ecosystem effects.

61 Conclusions: Management WATERSN Results Estuary Loading - Improved wastewater treatment results in the largest reduction in estuarine loading in LIS and Casco Bay (up to 57% for LIS). - Emissions reductions of NO x from utilities and vehicles will have the ancillary benefit of reducing N loading up to 14% for Casco Bay. - An integrated management plan that includes N controls on several sectors achieves maximum reductions.

Habibollah Fakhraei, Charles T. Driscoll Department of Civil and Environmental Engineering, Syracuse University

Habibollah Fakhraei, Charles T. Driscoll Department of Civil and Environmental Engineering, Syracuse University National Atmospheric Deposition Program Annual Meeting and Scientific Symposium Portland,