2003-09-23_REVISION - M1999034 - Laserfiche WebLink

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COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT WATER QUALITY CONTROL DIVISION WATER QUALITY PROTECTION SECTION GROLR~D-W.ATFR PERMIT GUIDANCE.. SUGGESTED MONITORING WELL SAMPLING PROTOCOL 8. GROIIHD-WATER S.4bIPLE COLLECTIOPi Ground-water sampling shall consist of ground-water sampling equipment decontamination, sample collection, sampling equipment decontamination and documentation of sample collection. 1. Collection of Ground-Water Samples Prior to initiating ground-water sampling activities, the monitoring person or personnel shall have cahbrated all field test equipment and decontaminated all equipment used to obtain aground-water sample. For a well with a ' dedicated pump no decontamination of the pump is necessary. In those circumstances where anon-dedicated pump (and generator) aze utilized, the pump and the tubing need to be thoroughly cleaned with a laboratory detergent, like Alconox, or equivalent, followed by several rinses with deionized water. If the same1~ equipment - ~bees$adly mated; "the equipment heed"tole cleaned with a stiff brush and hot-water detergent wash prior to the deionized water rinses. This same procedure is applicable for a bailer and its cable/rope. Purging of each well is to be accomplished by a dedicated pump or by a bailer or by a non-dedicated pump. During the purging process, temperature, pH, conductivity and dissolved oxygen are to be determined. Most permits do not regtrire dissolved oxygen at this time. However, in time, all permits shall require dissolved oxygen be determined during the purgmg, process and prior to sample collection. The measured temperature, pH and conductivity aze to be entered onto a log or sampling farm. After approximately three casing volumes, a ground- water sample will be collected once there is stabilization (within 10%) between the most recent sample and the previous two readings. If the meter readings for pH, temperature and conductivity do no stabilize, field personnel need only remove five casing volumes before taking aground-water sample. Pursuant to the monitoring requirements in the ground-water dischazge permit, ground water collected from the monitoring wells shall, typically, be analyzed for chloride, sulfate, nitrate and total coliform bacteria. In accordance with the "The Basic Standards for Ground Watei', the field personnel shall filter the samples for nihate, chloride and sulfate prior to preservation. [Refer to Regulation No. 41, "The Basic Standazds for Ground Water", to detemune which pazameters are required to be filtered prior to preservation.] The filter is a 45-micron filter. Some samples require preservative and some do not. The field personnel should obtain the reqused bottles from the laboratory that is performing the analyses. A11 samples aze to be iced in a cooler until they aze handed to Water in the well is to be withdrawn by sampling pumas, such as Waters inertia pumps or by using a baler (it is prefered that the bailer be a double check valve bailer). The sampling pumps may be dedicated to the upgradient and downgradient wells. Dedicated sampling pumps eliminate the potential for cross-contaminarion between wells and thus need for sampling equipment decontamination: in purging and sampling wells with inertia pumps, a flow rate of approximately one gallon per minute (gpm) is recommended rate to m;n;m;ze loss of any volatile compounds (This is only a concern for a volatile listed as a pemnt limit.) from the wafer to be sampled and analyzed. Provide a descrption and specifications of the pump(s') or bailer to be utilized.