5 Colo. Code Regs. § 1002-62.11
The provisions of 24-4-103; 25-8-202(1)(c) and (2); and 25-8-205, C.R.S. provide the specific statutory authority for consideration of the regulatory amendments proposed by this Notice.
The proposed amendments will change the definition of 7-day average and 30-day average contained in Section 10.1.4 of the regulation. Under current regulation three samples are required to establish a 7-day average or a 20-day average.
At this time, approximately 200 permit for smaller facilities require sampling less frequently (once/month or once/quarter) than the existing regulation requires. This was allowed in order to minimize sampling costs for smaller permittees.
In considering the proposed changes the Division examined the impact they would have on the affected permittees. Due to their inherent stability, effluent quality from lagoon facilities is fairly consistent. Therefore, one sample per month should give an accurate indication of effluent quality from lagoons and the change in the regulation will have little or no impact on the permittee. Small mechanical facilities, however, can exhibit large changes in process stability over a month. The proposed changes in the regulation could have a negative effect on mechanical facilities if the sampling requirements in their permits were to remain at the current level. In order to rectify this permits were to remain at their current level. In order to rectify this situation, permits for all small mechanical plants would be amended to include a sampling frequency of three times per 30 days. These changes would be reasonable as proper operation of mechanical facilities require frequent sampling for process adjustment.
Compliance monitoring done by the Division would be consistent with the sampling frequency in the permit of the affected facilities. In this way the results of the sampling series would be representative of the effluent quality from the facility during a 30-day period.
FISCAL IMPACT STATEMENT:
The change in the definitions for 30-day and 7-day average in 10.1.4 of the State Effluent Regulations will reduce State sampling costs for lagoon facilities and will increase sampling costs for permittees operating small mechanical plants. However, the increased sampling is consistent with that necessary for the proper operation of a mechanical plant treatment facility. Therefore, the Water Quality Control Commission finds this final agency action to be economically reasonable.
5 CCR 1002-62.11