If the provisions of §B of this regulation are met, agricultural nutrient and sediment credits may be generated from any of the following improvements that the Department determines will provide additional reductions in the discharge of farm nutrients and/or sediment: Existing or planned agronomic practices; Land conversion practices; or Installation of structural practices. Acceptable practices shall be consistent with the following: The practice does not result in the idling of whole or substantial portions of productive farmland to provide nutrient credits as determined by the Department after considering location, soil type, slope, and potential soil loss or erodibility; The practice is approved by a local soil conservation district but was not implemented using state or federal cost-share monies, or private cost-share monies identified by the Department, and is currently maintained by the owner/operator at his own expense; or The practice was implemented through a state or federal cost-share program, or a mitigation banking program, or with private cost-share monies identified by the Department, but has exceeded its specified lifespan as determined under the cost-share contract and is deemed by the Department as now being properly maintained by the owner/operator at his own expense. Credits generated on the agricultural operation will be calculated by the Department as follows: Category 1 Practices will be calculated using the MNTT. Category 2 Practices require review by an independent technical panel established by the Department to ascertain the appropriate nutrient and sediment removal efficiencies and determine effectiveness estimates. Category 3 Practices, together with specifications for installation, operation, maintenance, and monitoring, require scientific analysis and technical review by an independent technical panel established by the Department to evaluate nutrient and sediment removal efficiencies and determine best practice definitions and effectiveness estimates.