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Calculating Reportable Water Dissociable Nitrates

Use this spreadsheet to calculate the estimated nitrates generated at your facility from the neutralization of nitric acid.

Get started

  1. Download the Water Dissociable Nitrate Compounds Calculator (spreadsheet).
  2. Download the Fact Sheet: Reporting Water Dissociable Nitrates (PDF).
  3. Gather your facility's information on the amount of nitric acid used per year.

Additional Resources for

Using the nitrates calculation tool

  1. Enter the appropriate information in each of the shaded areas.
  2. Total generation of water dissociable nitrate compounds, in kilograms and pounds, is provided on the last line. 
  3. See the U.S. EPA guidance on reporting water dissociable nitrates for instructions on calculating “treatment efficiency.”
  4. If the molecular weight of the nitrate compound generated is known, enter this value for “Nitrate compound molecular weight (kg/kmol).”  If you are uncertain what the resulting nitrate compound may be, the molecular weight of NaNO3 (84.99 kg/kmol) may be used as a default.

Example threshold calculation

For this example, nitric acid (HNO3) is neutralized with sodium hydroxide (NaOH), producing nitrate compounds in the form of sodium nitrate (NaNO3). This calculation defines the amount of nitric acid (in pounds) a facility must neutralize to exceed the EPCRA/TURA reporting thresholds.

Neutralization reaction: HNO3 + NaOH –> NaNO3 + H2O

First, determine the molecular weight of HNO3 and NaNO3. 

MW HNO3 = 1 x 63 kg/kmol
MW NaNO3 = 1 x 85 kg/kmol 

Second, because the quantity of NaNO3 generated (in kilomoles) is equivalent to the quantity of HNO3 neutralized (in kilomoles), simply divide the molecular weight of HNO3 by the molecular weight of NaNO3. This gives a ratio of HNO3 neutralized versus NaNO3 generated, in terms of their molecular weights.

(63 kg/kmol HNO3)/(85 kg/kmol NaNO3) = 0.74

Third, multiply this ratio by the threshold reporting level for NaNO3.

The threshold is 25,000 lbs per year.
(0.74)(25,000 lbs) = 18,529 lbs.

In this example, a facility neutralizing 18,529 lbs or more per year of HNO3 with NaOH would trip the 25,000 lb reporting threshold and must report under EPCRA and TURA. See the respective rules reporting requirement guidelines for further information.

Notice about the nitrates calculation tool and reporting scenarios

This calculation is provided "as-is" without expressed or implied warranties. Because of the diversity of conditions under which this program may be used, it may not meet your requirements.

While nitric acid itself is a reportable chemical under the Emergency Planning Community Right-to-know Act (EPCRA) Section 313 (also known as the Toxics Release Inventory) and the Massachusetts Toxics Use Reduction Act (TURA), facilities should also be aware that the neutralization byproduct of nitric acid generates water dissociable nitrate compounds that are reportable above specific threshold levels under EPCRA and TURA.

The threshold for reporting coincidentally manufactured water dissociable nitrate compounds under EPCRA and TURA is 25,000 lb per year. For complete information, facilities should consult the U.S. EPA guidance on reporting water dissociable nitrate compounds.