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S E C O R the auger annulus during auger retraction to avoid shortcircuiting the well. The sand pack is tremmied to approximately two feet above the screen, at which time pre-development surging is performed to consolidate the sand pack. Additional sand is added as necessary to assure that the sand pack extends a minimum of two feet above top of screen. Following construction of the sand pack, a two foot thick bentonite seal is tremmied over the sand and hydrated in place. The remainder of the borehole is backfilled with neat cement grout. The well head is them capped with a locking cap and secured with a lock to protect the well from surface water intrusion and vandalism. The well head is further protected from damage with traffic a rated well box in paved areas or locking steel riser in undeveloped areas. The protective boxes or risers are set in concrete. The details of well construction are recorded on well construction logs. Following well construction, the wells are developed in accordance with agency protocols by intermittently surging and bailing the wells. Development is determined to be sufficient once pH, conductivity and temperature stabilize to within the 10 percent of the previous two readings and turbidity is below 10 NTUs. Wastewater collected during development is contained in 55-gallon DOT approved drums and stored on site pending laboratory results and disposal. A label is affixed to the drums indicating the contents of the drum, suspected contaminants, date of generation and the monitoring well number from which the waste water was generated. To evaluate groundwater gradient and groundwater elevation, the well heads are surveyed to an assumed or legal bench mark depending on the requirements of the project. Related Procedures: • Standard Procedure for Hollow Stem Auger Drilling • Standard Procedure for Soil Sampling—Split Spoon Sampling • Standard Procedure for Equipment Decontamination Soil Cuttings and RiinsatelPurge Water Disposal Soil cuttings, rinsate water generated during steam cleaning of equipment, and purge water from the development of the wells will temporarily be stored in DOT-approved, 55-gallon steel drums pending characterization and disposal.