Farming animals for meat has its problems but it does impose much stricter controls on the inputs. No farmer raising livestock for human consumption is feeding their animals contaminated food and water if there are other options available. If DuPont is upstream of your farm you're probably SOL but that's the exception not the rule.
[0] https://www.resilience.org/stories/2011-03-09/un-report-supp...
It means exactly what you heard. The USDA Organic label doesn't mean that organic crops are sustainable. The organic label doesn't address problems associated with commercial agriculture: monocultures, wide-spread use of pesticides, fertilizer run-off into streams/rivers/ponds/lakes causing them to become hypoxic, destruction of wetlands to create arable land etc.