1. Long-term Changes in Lamprey River Chemistry William H. McDowell University of New Hampshire

2. Sewage Treatment Plant Lamprey North River Withdrawal Lamprey at Packers Falls WHB Burley Demeritt Thompson Farm James Farm Precipitation Gauge Wet Deposition Stream Gauge Well Field Lamprey River Hydrologic Observatory

3. Research Questions 1.Are there long-term trends in Lamprey River chemistry driven by suburbanization? 2.Can variability in sub-basin surface water and groundwater chemistry be predicted by watershed attributes? 3.What drives long-term N balance in the Lamprey River watershed?

4. Long-term Lamprey Sampling

5. Nitrate Over Time in the Lamprey River ?

6. Monthly Nitrate in the Lamprey River

7. Dissolved Organic Carbon Over Time in the Lamprey River No significant trend with time

8. Surface water nitrate is best predicted by human population density Lamprey Sub-basins

9. Surface water nitrate is also related to urban cover and agricultural land use Lamprey, Ossipee and Oyster Sub-basins

10. Dissolved Organic Matter is Related to Wetland Cover Lamprey, Ossipee and Oyster Sub-basins

11. Nitrogen Inputs and Outputs from the Lamprey River Watershed Food Fertilizer Rain and dry deposition Input 14.5 kg N ha -1 yr -1 Output 0.8 kg N ha -1 yr -1 Retention 94% (or 13.7 kg N ha -1 yr -1 ) Stored or lost to atmosphere? 3.1 1.8 9.6