They enter streams either directly by flowing over the land, or indirectly through the groundwater by percolating through the soil. Also, nutrients that reach waterways through the groundwater may take decades to do so. All this makes accounting for reductions from nonpoint sources difficult. Changes in agricultural practices are rapid and must be carefully tracked. Cropping, silage, and planting practices are all subject to rapid change as the farming community seeks the most cost-effective operations.
Population growth is a major influence on the level of effort needed to achieve the strategy goals.
An increasing population in the region means that more reductions will be needed by the year 2000 to meet the overall nutrient reduction goals. For every two pounds of nitrogen being removed, one pound returns as a result of population growth and must be removed to keep pace with population growth. This emphasizes the need to remove nutrients at wastewater treatment plants. Completed nutrient strategies for tributaries from the Potomac River north are to be presented to the Executive Council in the fall of 1995. Interim strategies for tributaries further south, which have less of an impact on the Bay, will also be completed then.