Agenda - 01-21-1992 - Laserfiche WebLink

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]. 3 discharge into one of those waste treatment facilities. This alternative would obviously be very expensive. DEM believes that the proposed process for treatment and discharge represents the best available treatment technology, is economically feasible, will not cause irreparable harm to any of the receiving waters and. most importantly,'cleans up the groundwater problem. From an environmental standpoint, the mitigation of the groundwater is very important. because people drink groundwater with.no water treatment (unlike surface water supplies which are treated), because groundwater problems do not naturally tend to mitigate themselves (unlike single instance spills in surface waters), and because groundwater problems are more difficult to mitigate than surface water problems. I believe that DEM would support a public hearing on this permit as a public education process dealing with the seriousness and problems of a groundwater contamination problem, but I do not believe that DEM or the EMC will be dissuaded from issuing this permit. The proposed discharge permit involving Martin - Marietta's discharge of surface water runoff and ground water which collect in its rock quarry pit into Phil's Creek and University Lake represents a much more difficult problem for Orange County and for DEM. It is my understanding that some respected members of DEM staff have recommended that this permit application be denied, because NPDES permits are not allowed in waters presently classified as WS -I. A major part of the present definition of the WS -I classification is that it contains no NPDES discharge. In all probability, the proposed Martin - Marietta discharge does not represent a serious threat to water quality, in that the objectionable components of the discharge would be limited to suspended fine rock particles which are anticipated from the mining and blasting operations. Two of the effluent parameters limited by the proposed permit are settleable solids and turbidity, which deal with solids suspended in the water and clarity of the water. Considering the probable lack of an organic component to the settleable material, it is-unlikely that even a major violation of these effluent standards would represent a serious water quality threat. One parameter that is specified and that does represent a potential water quality problem is pH. Excessively acidic or alkaline water represents at threat to plant and aquatic life in the receiving stream. Quarry operations have a potential for causing fluctuations in water pH because groun.dwaters or stormwater runoff which collect in the quarry pit are often exposed to limestone. which causes the water to become alkaline (high pH), or to acid bearing rock strata, which caused water to become acidic (low pH). Generally, I would have to classify the potential threat to water quality from pH problems to be of low probability. The most serious problem that I can see from the approval of this NPDES permit is one of precedent. The University Lake watershed is one