When the beaches of Venice started experiencing excessive
contamination, local officials suspected a common source: human feces.
However, that wasn't the case. After studying six DNA samples, they also
ruled out dog and bird wastes as the cause of the problem. The next
step was to make an educated guess as to what was causing the pollution,
and by process of elimination, tests pointed a finger at rat and
raccoon feces. Case solved? Hardly! Whereas they could have repaired
compromised sewer lines, how can you tell a wild creature where to do
his duty?
Anyone might conclude that the Department of Health was overjoyed to finally know the reason behind the higher-than-acceptable levels of fecal coliform and enterococcus bacteria. The fact that there had been no rain yet the worst of the pollution had been concentrated near two pipes which were used to drain storm water into the gulf had them stymied. Then they discovered that the water flow into the area was caused by homeowners watering their lawns since there was no rain. This clean water was particularly appealing to thirsty wildlife who congregated at the mouth of these pipes in order to drink during dry periods of time.
The good news here was the fact that human swimmers are less likely to contract diseases from animal feces. However, the problem in general wasn't good, and engineers had to come up with ways to cut down on the contamination. A common misconception is that screens can be used to stop wildlife getting into pipes such as these. True, it's a solution that could work except for the fact that screens clog with debris which, during heavy rainfall, could cause the sewers to back up.
The solution that seems to be working best so far is keeping watch of the amounts of contamination in these areas. If a problem build-up of bacteria is found, city workers can be assigned the task of cleaning out the pipes. Unfortunately, operating this aggressive maintenance procedure has escalated costs to unacceptable levels. A permanent fix would be far less costly, that is provided a viable one can be found.
Starting in August, the city plans to try revamping the way the sewer system runs in order to stop the accumulation of bacteria. By rerouting two of the worst water runs so as to detour them through a shallow swale, the water will percolate into the sand, the ultraviolet rays of the sun will help to break down the colonies of bacteria. Two other water systems will be connected to vaults where the water will be filtered and UV treated before being pumped offshore.
Anyone might conclude that the Department of Health was overjoyed to finally know the reason behind the higher-than-acceptable levels of fecal coliform and enterococcus bacteria. The fact that there had been no rain yet the worst of the pollution had been concentrated near two pipes which were used to drain storm water into the gulf had them stymied. Then they discovered that the water flow into the area was caused by homeowners watering their lawns since there was no rain. This clean water was particularly appealing to thirsty wildlife who congregated at the mouth of these pipes in order to drink during dry periods of time.
The good news here was the fact that human swimmers are less likely to contract diseases from animal feces. However, the problem in general wasn't good, and engineers had to come up with ways to cut down on the contamination. A common misconception is that screens can be used to stop wildlife getting into pipes such as these. True, it's a solution that could work except for the fact that screens clog with debris which, during heavy rainfall, could cause the sewers to back up.
The solution that seems to be working best so far is keeping watch of the amounts of contamination in these areas. If a problem build-up of bacteria is found, city workers can be assigned the task of cleaning out the pipes. Unfortunately, operating this aggressive maintenance procedure has escalated costs to unacceptable levels. A permanent fix would be far less costly, that is provided a viable one can be found.
Starting in August, the city plans to try revamping the way the sewer system runs in order to stop the accumulation of bacteria. By rerouting two of the worst water runs so as to detour them through a shallow swale, the water will percolate into the sand, the ultraviolet rays of the sun will help to break down the colonies of bacteria. Two other water systems will be connected to vaults where the water will be filtered and UV treated before being pumped offshore.
No comments:
Post a Comment