The EPI measures water quality in terms of “age-standardized disability-adjusted life-years lost per 100,000 persons (DALY rate) due to exposure to unsafe drinking water”

Not just Michigan with lead in their water pipes

The impact of lead on neurodevelopmental effects in children even at low levels of exposure is well established. Population and toxicokinetic modeling studies have found a clear relationship between water lead levels and blood lead levels in children at low levels of lead in drinking water

The IARC classes lead as a probable human carcinogen. Lead damages the nervous system and can lead to reproductive problems.

It sounds like lead in water pipes isn’t directly lethal so that would explain why they don’t count it in the numbers from that site

The definition on that website sounds like they just count people dying as direct result of the water (Ex dysentery)