Could the nightmarish toxic sludge at the bottom of the Gowanus be frozen in place with a “clay-based seal” called AquaBlock? Well, it’s one of the less expensive solutions to detoxing the canal being considered by the Army Corps of Engineers. The Corps is coming up with options for dealing with the horror show of pollution that makes up the canal bed. The traditional solution would be dredging, but it would be far more costly. Dredging would also be controversial because it would stir up and possibly spread toxic sediment that currently sits at the bottom. The Brooklyn Daily Eagle reports on a presentation made at a recent community meeting (that somehow did not appear on our radar screen). The downside of such a solution is that the technology’s effectiveness is unproven over the long run; it is relatively new and has only been used in a small number of places. It could also be unpopular with some people as it keeps all of the toxins in place. “Capping” toxic sites and leaving some pollutants, however, has become a fairly common practice as a less expensive alternative to full cleanups. Even if the solution were to prove acceptable to policymakers, however, it does not address the ongoing problems of pollutants leaching into the canal from nearby sites and the serious problem of raw sewage flowing into the canal during rainstorms. Those are very different and critical ongoing issues that will impact any canal cleanup efforts.