2.    Spring a ____

4.    A slender, flexible auger used to dislodge clogs in
plumbing

7.    Ion removal system

10.  Prevents flooding

12.  A channel or pipe that carries off surplus  liquid

13.  A light blow

15.  Cleanse

16.  A small drop

18.  One element in ancient and medieval philosophy

19.  Stopped up

20.  Collects human waste

21.  A tool used to rotate plumbing pipes and fits
different pipe diameters

1.   On-demand system

3.   No-dig

5.   Seals a gap

6.   U-shaped portion of pipe designed to trap liquid or gas to
prevent unwanted flow

8.   Carries waste underground

9.   Controls the flow

11.  Sealant in plumbing

14. Bendable network media

17. Regulator