If operators considered the ponds as a small biological treatment unit rather than a "wide spot in the ditch", the problems listed above can be remedied with ease.
Secondly, we monitor the pond visually to determine if conditions are changing. When you start to see oil sheen on the pond, I recommend responding by using bioaugmentation to rapidly degrade the petroleum hydrocarbons. This process efficiently degrades the hydrocarbons onsite while minimizing risks to the environment. If the ponds serves fueling stations and large parking lots, using bioaugmentation on a periodic basis can keep the petroleum degrading microbes at high concentrations while waiting on the hydrocarbons washed in by rain events.
In addition to improving hydrocarbon removal, the use of mixers and bioaugmentation will help control algae growth that causes odors and reduces pond aesthetics.