Oregon Administrative Rules › Chapter 690 - WATER RESOURCES DEPARTMENT › Division 230 - STANDARDS AND PROCEDURES FOR LOW-TEMPERATURE GEOTHERMAL PRODUCTION AND INJECTION WELLS AND EFFLUENT DISPOSAL SYSTEMS › Section 690-230-0085 - Pump Testing of Low-Temperature Geothermal Injection Wells With an Anticipated Injection Rate Exceeding 15,000 Gallons Per Day

Current through Register Vol. 63, No. 7, July 1, 2024
(1) Low-temperature
			 geothermal injection wells (other than flowing artesian wells) with an
			 anticipated injection rate of greater than 15,000 gallons per day, shall be
			 pump tested for a period for at least four hours. The pump test shall occur
			 after the owner's pump test plan is approved by the Director, and prior to
			 injecting into the well. The results of this test do not need to appear on the
			 water well report. This test shall be in addition to the minimum one-hour test
			 requirement under OAR
			 690-210-0370.
			 Requirements for conducting the minimum four-hour pump test as discussed in
			 this section (this type of test) are as follows:
(a) Prior to testing, the well shall be idle
			 for a period of at least four hours;
(b) The static water level in the well shall
			 be measured at least three time, no less than twenty minutes apart, during the
			 hour prior to pumping the well;
(c)
			 The water shall be pumped into or from the well at a measured and steady rate.
			 The rate shall approximate the maximum anticipated injection rate;
(d) The pump discharge shall be controlled as
			 much as possible to maintain a constant rate during the test. The discharge
			 rate shall be as close as reasonably possible to the anticipated injection rate
			 during normal use of the well. Discharge rate shall be recorded at the
			 beginning of the test and once every hour thereafter;
(e) Water levels in the well shall be
			 physically measured by a standard and acceptable method. Visual estimation of
			 water level is not acceptable. Acceptable methods include:
(A) An electric water level measuring
			 tape;
(B) An air line dedicated to
			 the well;
(C) An acoustic
			 sounder;
(D) An electronic pressure
			 transducer; or
(E) Other water
			 level measuring methods approved in advance by the Director.
(f) The water level measurements
			 shall occur at least at the minimum frequency outlined below: Time period --
			 Water level measurement schedule:
(i) First 10
			 minutes -- No more than 2 minutes apart;
(ii) 10 to 30 minutes -- No more than 5
			 minutes apart;
(iii) 30 to 100
			 minutes -- No more than 15 minutes apart;
(iv) 100 to 240 minutes -- No more than 30
			 minutes apart.
(g) After
			 pumping stops, water level measurements shall be collected for a time equal to
			 that of the pumping period, or until the well reaches 90 percent recovery from
			 the maximum drawdown, whichever occurs first. Recovery water level measurements
			 shall be collected on the same time schedule as described in subsection (1)(f)
			 of this rule;
(h) The pump
			 discharge shall be physically measured by a standard and acceptable method.
			 Visual estimation of flow rate is not acceptable. Acceptable methods include:
(A) A properly installed flow meter, designed
			 for geothermal use, which is functional and calibrated within reasonable limits
			 for the type of meter;
(B) A
			 properly installed weir or flume;
(C) A properly installed and calibrated
			 orifice plate and manometer;
(D)
			 Known volume/time calculations (including calibrated bucket and stopwatch up to
			 60 gallons per minute);
(E)
			 Properly installed and used ultrasonic flow measuring devices; or
(F) Other discharge methods approved in
			 advance by the Director.