Section 502.520  Changes to the Nutrient Management Plan

When a CAFO owner or operator makes changes to the CAFO's nutrient management plan previously submitted to the Agency, the procedures in this Section are applicable.

a)         The CAFO owner or operator must identify changes to the nutrient management plan, except that the results calculated under Sections 502.515(d)(3) and (e)(3) are not subject to this Section.  These calculations may be revised without submittal to the Agency if the calculation revisions do not change the terms of the nutrient management plan.

b)         The Agency must determine whether the changes to the nutrient management plan necessitate revising the terms of the nutrient management plan incorporated into the permit issued to the CAFO.

1)         If revising the terms of the nutrient management plan is not necessary, the Agency must notify the CAFO owner or operator and, upon that notification, the CAFO may implement the revised nutrient management plan.

2)         If revising the terms of the nutrient management plan is necessary, the Agency must determine whether the changes are substantial changes as described in subsection (d).

3)         If the Agency determines that the changes to the terms of the nutrient management plan are not substantial, the Agency must notify the owner or operator and inform the public of any changes to the terms of the nutrient management plan that are incorporated into the permit.

c)         If the Agency determines that the changes to the terms of the nutrient management plan are substantial, the Agency must notify the public and make the proposed changes and the information the CAFO owner or operator submits available for public review and comment.

1)         The process and time limits for submitting public comments and hearing requests, the hearing process if a request for a hearing is granted, and the process for responding to significant comments received during the comment period will follow the procedures applicable to draft general permits found in Section 502.310(d) through (f).

2)         The Agency will require the CAFO owner or operator to further revise the nutrient management plan if necessary to approve the revision to the terms of the nutrient management plan incorporated into the CAFO's permit.

3)         Once the Agency incorporates the revised terms of the nutrient management plan into the permit, the Agency must notify the owner or operator and inform the public of the final decision concerning the revisions to the terms and conditions of the permit.

d)         Substantial changes to the terms of the nutrient management plan incorporated as terms and conditions of a permit include:

1)         Adding new land application areas not previously included in the CAFO's nutrient management plan; except that, if the land application area that is being added to the nutrient management plan is covered by the terms of a nutrient management plan incorporated into an existing NPDES permit in compliance with Section 502.515, and the CAFO owner or operator applies livestock waste on the newly added land application area in compliance with the existing field-specific permit terms applicable to the newly added land application area, adding new land would be a change to the new CAFO owner's or operator's nutrient management plan but not a substantial change for this Section;

2)         For nutrient management plans using the linear approach stated in Section 502.515(d), changes to the field-specific maximum annual rates of land application (pounds of nitrogen and phosphorus from livestock waste).  For nutrient management plans using the narrative rate approach, changes to the maximum amounts of nitrogen and phosphorus derived from all sources for each crop;

3)         Adding any crop or other uses not included in the terms of the CAFO's nutrient management plan and corresponding field-specific application rates expressed in accordance with Section 502.515; and

4)         Changes to site-specific components of the CAFO's nutrient management plan, when the changes are likely to increase the risk of nitrogen and phosphorus transport to waters of the United States.

(Source:  Amended at 48 Ill. Reg. 3196, effective February 15, 2024)