A. Retirement of credits.

1. Pursuant to the requirements of § 62.1-44.19:20 of the Act, 5.0% of the total credits certified will be retired by the department at the time of nutrient credit certification and will not be placed on the registry for exchange.

2. When phosphorus credits are acquired in accordance with 9VAC25-870-69, the associated nitrogen credits generated by the nutrient credit-generating project will be retired and removed from the registry by the department.

3. When nitrogen credits are acquired for purposes other than compliance with 9VAC25-870-69, the associated phosphorus credits generated by the nutrient credit-generating project shall not be available for compliance under 9VAC25-870-69.

4. Except as limited by this subsection, associated nitrogen and phosphorus credits generated by a nutrient credit-generating project may be exchanged independently.

B. Schedule of release of nutrient credits. The department shall establish a schedule for release of credits as follows:

1. For nutrient credit-generating projects using land use conversion, 25% of the credits will be released by the department after the department has verified completion of the conditions of the nutrient credit certification. For afforestation projects, an additional 25% of credits will be released by the department after the site has been planted with a minimum of 400 woody stems per acre. The remaining balance of credits will be released by the department after it is satisfied that the implementation plan's performance criteria required pursuant to 9VAC25-900-120 has been achieved. When a request for credit release is made concurrently with the application for nutrient credit certification from land conversion practices, the concurrent 25% initial release, and additional 25% release if planting has occurred, shall be processed on the same timeline as the application as provided in 9VAC25-900-80 C. When the request for credit release is from a previously approved land conversion project, the department shall schedule a site visit, if warranted, within 30 days of the request and shall deny, approve, or approve with conditions the release of the remaining 75% of the nutrient credits within 15 days of the site visit or determination that a site visit is not warranted.

2. For nutrient credit-generating projects using wetland or stream restoration, after construction 25% of the credits may be released by the department after the department has verified completion of the conditions of the nutrient credit certification. Every monitoring year thereafter, 25% of the credits may be released if all performance standards are met, the area or channel is stable, and, for streams, evidence is presented that a bankfull event occurred within the monitoring year. For streams, if a bankfull event did not occur, but performance standards are met and the channel is stable, 10% of the credits may be released. No additional credits will be released after the fourth monitoring year until a bankfull event has occurred. After the fourth monitoring year, if a bankfull event occurs, the channel is stable, and all performance standards are met, 25% of the credits may be released that monitoring year, not to exceed the remaining credits available. The schedule for release of credits shall also require, prior to the release of credits, the approval of any required financial assurance mechanism established pursuant to Part VI (9VAC25-900-230 et seq.) of this chapter. The department may accelerate the release of a maximum of 50% of nutrient credits from a stream restoration project based on (i) a determination that the level of risk for restoration failure is low; (ii) the provision of additional financial assurance in an amount adequate to cover the cost of project repair or replacement in the event of failure; and (iii) the experience of the applicant or the applicant's agents who will implement the stream restoration project.

3. For nutrient credit-generating projects using practices other than land use conversion or wetland or stream restoration, the schedule for release of credits will be determined by the department on a case-by-case basis and provided to the applicant with the nutrient credit certification. For projects using structural BMPs, the schedule shall also require, prior to release of credits, the approval of any required financial assurance mechanism established pursuant to Part VI (9VAC25-900-230 et seq.) of this chapter.

C. Registration of nutrient credits. Credits will be placed on the registry and classified as term or perpetual credits by the department. The registry will also indicate the number of credits that have been released for exchange. Only credits released by the department are available for exchange.