As I write this piece on Day 70 of the Gulf oil spill, the start of the 2010 hurricane season threatens to further slow the containment of the Deepwater Horizon well.

But obviously, as we've moved into the third month of the ongoing disaster, the weather is only the latest of the numerous setbacks suffered in the struggle to shut down the broken well. A quick recap of the biggest challenges BP and the federal government have faced to date:

• The failure of the original containment dome installed by British Petroleum on May 7-8, clogged by the formation of chemical crystals produced from a mixture of gas and frigid seawater.
• The May 11 decision to abandon the installation of a smaller containment "top hat."
• The failure of the May 26-29 "top kill" procedure to plug the broken blowout protector.
• The June 3 failure of the diamond-edged saw intended to produce the clean cut needed to smoothly cap the well riser. A robot, wielding shears, eventually produced a jagged cut that permitted the placement of a containment cap and the partial capture of the estimated 35,000-60,000 (and counting) barrels of oil gushing daily from the broken pipe.
• The June 23 temporary displacement of the containment cap by a robot -- a mishap fortunately corrected shortly afterward. 

As this suggests, there have been few decisive answers to the engineering challenges posed by Deepwater Horizon. BP's containment efforts, and they have been herculean, numerous, and ongoing, have yet to halt the leak, and the gargantuan spill appears almost certain to continue until a relief well is completed in August. In the interim, the oil will continue to flow and to despoil the Gulf ecosystem and economy.

My own experience suggests that environmental pollution, even comparatively small discharges, can be notoriously difficult to fix. About 10 years ago, I unexpectedly found myself directing the clean-up of a building-scale environmental emergency. At the time I was managing a national commercial real estate portfolio. One of my properties was a research and development project tenanted by a manufacturing firm under a long-term lease. After years of occupancy, the tenant exercised a termination option and vacated.

Subsequent inspection and testing revealed that, in blatant violation of its lease, the tenant had left behind a witch's brew of chemical residues -- including dust from silver and mercury (both toxins) -- that had penetrated the building's plumbing and ventilation systems. Testing and clean-up -- which required the use of space-suited technicians, quantities of crime scene tape, and prominent haz-mat postings -- took upwards of three months. And (unlike Deepwater Horizon) we were working on firm ground, rather than at a depth of 5,000 feet below sea level.

My experience with that manufacturer leads me to believe that environmental contingency planning is typically given short shrift by many businesses, unless substantial financial liability is anticipated in the event of environmental problems. That was certainly the case with my tenant. The recently revealed shortcomings of oil industry containment plans for deepwater spills suggest that my concerns about the quality of corporate planning for environmental contingencies are hardly misplaced.

Next page: How to stop another spill before it happens.