Isotope Studies

Are there elevated levels of nitrate in your monitoring wells or production wells? Is the source of this nitrate your dairy? Or is it from fertilizer applications on the adjacent farm or leaching from a domestic septic system?

GGI has developed a simplified procedure for determining the potential source nitrate in groundwater by using measurements of stable isotopes in the water, GGI uses these results to identify the source based on our in-house database. GGI has compiled a database of isotope signatures from different published sources and unpublished sources.

A typical isotope study involves:

• Collection of groundwater samples and depths-to-water measurements from all monitoring wells and production wells where possible.
• Development of a potentiometric map for information regarding groundwater flow and gradient.
• Analyses of the groundwater for stable isotopes of nitrogen (15N), oxygen (18O) and deuterium (2H) along with nitrate (nitrogen-NO3), chloride (Cl-), total Kjeldahl nitrogen (TKN), and total dissolved solids (TDS).
• Development of nitrate “fingerprints” for the operation and surrounding potential sources.

Example plot of several dairy results and interpretation.

All of these components are integrated by our experts to produce a summary report that can determine the source of the nitrate at a facility.