I heard one reporter ask why they did not replace all the water pipes in Flint. Since the reporter had no idea what she was saying and apparently the Government leader was also clueless we got what we can expect from the media; nonsense.
But some thoughts may be worthwhile.
1. Most old cities have no idea where all these pipes are. Records are not that great nor are they accurate and things move. So trying to find them is tough.
2. The cost to even dig and install new pipes is fantastic. My guess is about $5 million per mile of pipe, maybe even more.
3. However the old pipes can be used, somewhat.
4. In the oil industry they face the same problems. Oil pipeline get what is called a biofilm growth. Like arteries in old folks. What they do is use a device called a "pig" that has razor sharp blades that rotate and cut off all the old biofilm. Let's assume you can do that in the old lead pipes. The tools exist and they work. Much less that the replacement costs. And the pigs collect the biofilm masses and expel them as it move forward.
5. But you still have lead. So what you do is install a PVC or equivalent pipe sheath inside the lead. This keeps the lead out.
6. The you coat the PVC with nano Selenium to inhibit future biofilm growth. Real cheap.
7. This replaces 95% of the lead pipe and provides a stable bacteriostatic flow path.
8. It may leave some residual lead local pipes in homes but they were there anyway. You will reduce the lead burden by well over 99.9%, well withing EPA limits.
9. When using the pigs you also use modified GPS to fully map the system for future reference.
10. Estimates are about $250,000 per mile of pipe.
Let's see what the Government comes up with!