Question

__________ wells are constructed when low yielding groundwater sources are found relatively close to the surface, usually under 30 m (100 ft.). These are constructed using a rotary bucket auger.

(a) Cap

(b) Drilling

(c) Bored

(d) Surface

This question was addressed to me during an interview.

My question is based upon Wells topic in portion Irrigation Works, Culverts, Bridges and Wells of Civil Engineering Drawing

Answer 1

Correct option is (c) Bored

Easiest explanation: They are usually completed by perforating the casing (also called cribbing) or using a sand screen with continuous slot openings (Bored Well). One advantage of bored wells is the large diameter of the casing, from 45-90 cm (18-36 in.). It provides a water storage reservoir for use during peak demand periods. A disadvantage of utilizing a shallow groundwater aquifer is that it generally relies on annual precipitation for recharge. Water shortages may occur following long dry periods in summer and extended freeze up during winter months. It can also be more susceptible to contamination from surface land-use activities.