Worksite Logistics

For residential water wells, drilling normally takes one to three days to complete depending on depth and drilling conditions. Adequate room around the drill site is necessary for safely conducting work. The drilling machine and support truck are 35’-45’ long semi-trucks. The site must accommodate safe hoisting of tooling and materials between the two trucks. A third “chase” pickup often follows. Overhead clearance needs to be considered for drilling and raising/lowering of the drill derrick. For deeper or more difficult wells additional equipment may be necessary.

Seasonal changes can affect accessibility of drilling equipment. Optimal drilling access is typically from May to October due to many drill sites requiring drier ground conditions. Customers with adequate access or those willing to build infrastructure for the drilling equipment can be drilled in winter months.

Drilling methods/construction

Air-rotary drilling is the most common drilling method used in Southern Oregon due to its effectiveness. This method utilizes a rotating drill bit at the end of drill string to cut through the formation. Compressed air, plumbed through the center of the drill string, evacuates the material to the surface and often powers drill tooling down the hole. Water is injected to provide additional lifting, cooling and dust control. The excavated material, known as “cuttings”, is typically a combination of the native formation and water injected by the driller. Once the aquifer is reached, water from the well itself will be brought to the surface in the same manner. Learn more about our capabilities.

As the well is constructed, well casing (primarily steel) is used to stabilize the bore hole through the unconsolidated formations until competent bedrock or the desired depth is reached. State laws require a sanitary seal to prevent contaminants from entering the well and aquifer. Sealing rules can be complicated, driven on the lithology and aquifer characteristics. Legally, all wells must be sealed a minimum of 18′ with an approved sealing material, however most areas require a deeper seal dictated by the geology encountered. Primary approved sealing materials are bentonite clay and cement.

Well design decisions regarding sealing, casing, screen placement, and final bore depth are often the difference between success and failure of a well. Proper construction techniques, including well development, are important to a quality well. Incorrect well design or construction could lead to a collapsing bore, bacteria, turbid water, inefficient production, or other issues.

Once the well is complete, it is chlorinated, capped and assigned a well identification tag. The driller will produce and submit a well log to the state serving as an official record for well construction. At this point, the well is ready for installation of pump equipment and connection. We work closely with quality pump installers in our region, and can refer as necessary.