A drilled well consists of a hole bored into the ground, with the upper part being lined with casing. The casing prevents the collapse of the borehole walls and (with a drive shoe or grout seal) prevents surface or subsurface contaminants from entering the water supply.The casing also provides a housing for a pumping mechanism and for the pipe that moves water from the pump to the surface. drilled well consists of a hole bored into the ground, with the upper part being lined with casing. The casing prevents the collapse of the borehole walls and (with a drive shoe or grout seal) prevents surface or subsurface contaminants from entering the water supply.
Hives and angioedema can be caused by: 1  Foods. Many foods can trigger reactions in people with sensitivities. 2  Medications. Almost any medication may cause hives or angioedema. 3  Common allergens. Other substances that can cause hives and angioedema include pollen, animal dander, latex and insect stings.  Environmental factors.
Urticaria (hives) - Causes. Causes of urticaria. Urticaria occurs when histamine and other chemicals are released from under the skin's surface, causing the tissues to swell. Short-term (acute) urticaria. The triggers of acute urticaria are unknown in around half of all cases. Long-term (chronic) urticaria.