Section 096-519-6 - Adjustment of interim effluent limits for the discharge of mercuryA.Basis for adjustment. After interim effluent limits established by the commissioner are effective, a licensee may, with proper documentation, request adjustment of those limits for the reasons listed below. The department may approve an adjustment if it determines that the circumstances presented may result in an interim effluent limit that is significantly different from that calculated pursuant to Section 4(B). (1) Water conservation. A licensee has implemented permanent water conservation practices that result in a lesser volume of discharge. A reduction in discharge volume may not result in a greater total quantity of mercury being discharged.(2) Production changes. A licensee institutes different levels or types of production or accepts new sources of influent wastewater. Such changes must be mitigated or offset to the maximum extent possible with implementation of best management or pollution prevention practices to reduce or prevent the introduction of mercury. A production change may result in an increase in the concentration or quantity of mercury discharged, but not both.(3) Seasonal changes. Seasonal changes may cause a significant and uncontrollable variation in the performance of a treatment facility. A licensee's intake water may experience a higher concentration of mercury during certain seasons of the year. Higher seasonal rainfall may increase the flow through a wastewater treatment facility causing additional mercury loadings to the facility.B. Procedures. In making adjustments to interim effluent limits, the department shall, to the extent possible, utilize the procedures described in, or similar to, Section 4. C.Additional testing. In order to support adjustment of interim effluent limits, the department may require a licensee to conduct more testing than otherwise required by this rule.06- 096 C.M.R. ch. 519, § 6