The user of this guide is not assumed to be a trained technical practitioner in the water quality field. The guide is an assembly of the components common to all aspect of watershed nutrient monitoring and fulfills a need in the development of a common framework for a better coordinated and a more unified approach to nutrient monitoring in watersheds.

Limitations—This guide does not establish a standard procedure to follow in all situations and it does not cover the detail necessary to meet all of the needs of a particular monitoring objective. Other standards and guides included in the references describe the detail of the procedures.

1.1 Purpose—This guide is intended to provide general guidance on a watershed monitoring program directed toward the plant nutrients nitrogen and phosphorus. The guide offers a series of general steps without setting forth a specific course of action. It gives assistance for developing a monitoring program but not a program for implementing measures to improve water quality.

1.2 This guide applies to waters found in streams and rivers; lakes, ponds, and reservoirs; estuaries; wetlands; the atmosphere; and the vadose and subsurface saturated zones (including aquifers). This guide does not apply to nutrients found in soils, plants, or animals.

1.3 Nutrients as used in this guide are intended to include nitrogen and phosphorus in dissolved, gaseous, and particulate forms. Specific species of nitrogen include: nitrate, nitrite, ammonia, organic, total Kjeldahl, and nitrous oxide. The species of phosphorus include total, total dissolved, organic, acid-hydrolyzable, and reactive phosphorus as described in (2)

1.4 Safety—Health and safety practices developed for a project may need to consider the following:

1.4.1 During the construction of sampling stations:

1.4.1.1 Drilling practices during monitoring well installations,

1.4.1.2 Overhead and underground utilities during monitoring well drilling,

1.4.1.3 Traffic patterns/concerns during sampling station installation,

1.4.1.4 Traffic patterns/concerns during surveying sampling station locations and elevations,

1.4.1.5 Drilling through materials highly contaminated with fertilizers, and

1.4.1.6 Installing monitoring equipment below the soil surface.

1.4.2 During the collection of water samples:

1.4.2.1 Using acids for sample preservation,

1.4.2.2 Sampling during flooding events and ice conditions,

1.4.2.3 Traffic on bridges,

1.4.2.4 Condition of sampling stations following flood events,

1.4.2.5 Sampling of water or soils, or both, highly contaminated with fertilizers,

1.4.2.6 Conditions of sampling stations resulting from vandalism,

1.4.2.7 Adverse weather conditions, and

1.4.2.8 Transporting liquid samples.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.