The Congressional Budget Office - a flawed bureaucracy but still the best governmental agency at projecting cost in the history of the world - has projected $22 billion to settle these cases.
There are two schools of thought on this. One is that the CBO has made meaningful projections based on estimated Camp Lejeune lawsuits they expect to be filed. The other school of thought is that even the CBO cannot project this. It is like trying to project where the stock market will be in 10 years. So the $22 billion is likely a floor that can be raised if more claims come in than they hoped.
It is also important to understand there may be a range of settlements from over $1 million per person to as little as $25,000. Cancer and Parkinson's disease Camp Lejeune lawsuits are likely to fetch higher settlement amounts. Some other injuries might have smaller water contamination settlement compensation payouts.