Can high aluminum on my labs be due to not checking the water system at regular intervals?

Only if the level of the aluminum in the water is actually high and it went undetected.

Other likely culprits would be medication and cooking implements like pots, pans and storage containers. This is even more true if the food is acidic.

Also depending on your own drinking water source, most municipalities add alum to the water to help clarify and filter it.

Yes, however:

A possible culprit is specimen handling - Aluminum levels need to be drawn in special tubes, the centrifuged and refrigerated quickly. You may ask to have the test repeated.

If there is a high level of aluminum in the dialysis water, the other patients would also be affected. A sudden and unexplained outbreak of high serum aluminums at the dialysis center would be quickly noticed by the physician and staff.

Dialysis water systems usually remove aluminum by reverse osmosis (aka RO). Ro works by forcing the feed water across a membrane under pressure while allowing some water to flow to the drain. Because impurities like aluminum tend to remain dissolved, the greatest part (usually above 90%)stays with the water flowing down the drain. Many factors influence the level in the water produced by RO, but the greatest influence is the level in the feed water. As Chuck wrote, many city water systems add alum to make suspended solids clump together, so they can be more easily removed. This is especially true with systems using a surface supply, rather than a well. Surface systems tend to add more alum when the water level in the source is low, as is typically true in late summer.

I asked my doctor about it, he said its one of those lab levels thats to be expected for dialysis patients. My aluminum was 19. He said he wouldn't worry about it unless it was more like 50. Nevertheless, I'd like to see if taking measures like changing to bottled water and getting rid of any aluminum pans would help. I looked it up and aluminum affects the bones.