What is the purpose of the sanitary seal and annular grout in well construction?

• A. The sanitary seal prevents surface water intrusion into the well; annular grout isolates the aquifer from surface contamination and supports the casing.
• B. The sanitary seal reduces pumping efficiency; annular grout increases energy use.
• C. The sanitary seal insulates the wellhead; annular grout increases the well diameter.
• D. The sanitary seal prevents root intrusion; annular grout decorates the wellhead.

Answer: (A)