Secondary treatment was established to protect streams from overload of nitrates. The Point Loma plant uses an innovated process that is more reliable because it is chemically based instead of biology based (primary treated sewage is feed to bacteria that use the nitrates as food). In advanced primary treatment, which I think should be renamed as chemical secondary, most everything that is not a salt is electronically charged, clings together and settles out of the water. It is much more advanced then primary treatment. The difference is the Point Loma Plant does not remove as many of the nitrates because these are salts.
Nitrates are a normal part of the ecology and rain is high in nitrates. If you compare arid areas with for example areas rich in animal life such as Washington state, arid areas have a nitrate deficit. Compare the dilution of treated wastewater in a narrow stream that receives discharges from plants every few miles, to a discharge into a huge body of water 320’ deep and endlessly wide. An analogy can be made that this is equivalent to the difference between fertilizing your law with six huge bags of nitrate fertilizer to throwing three grains of it on your lawn. The first obviously kills everything, the second may have an impact but it is not detectable and in our arid area, more would be closer to the nitrate levels found where it rains.
To put this in perspective, if you used the same criteria of no net impact on all life and applied that to the land, we would not have been able to construct a single building or road in San Diego. Walking on your property could have more negative impact on animal life then what we are doing to the ocean.
The area that receives the plume 4.5 miles out at sea is not sensitive habitat like tide pools or even kelp beds but what seams like an endless expanse of sand bottom, that to the untrained person looks like it supports no life. If some of this very diluted (and sanitized) water should happen to get back to shore, it would be a benefit to the kelp beds. If you want more life in the ocean, and to support our fishing industry, the logical solution would be to build man made rock outcrops that would expand our kelp beds. These would then use the nitrates and offset any difference our treated water makes in the ocean.
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San Diego Gets Pollution Waiver For Point Loma Plant
Secondary treatment was established to protect streams from overload of nitrates. The Point Loma plant uses an innovated process that is more reliable because it is chemically based instead of biology based (primary treated sewage is feed to bacteria that use the nitrates as food). In advanced primary treatment, which I think should be renamed as chemical secondary, most everything that is not a salt is electronically charged, clings together and settles out of the water. It is much more advanced then primary treatment. The difference is the Point Loma Plant does not remove as many of the nitrates because these are salts.
Nitrates are a normal part of the ecology and rain is high in nitrates. If you compare arid areas with for example areas rich in animal life such as Washington state, arid areas have a nitrate deficit. Compare the dilution of treated wastewater in a narrow stream that receives discharges from plants every few miles, to a discharge into a huge body of water 320’ deep and endlessly wide. An analogy can be made that this is equivalent to the difference between fertilizing your law with six huge bags of nitrate fertilizer to throwing three grains of it on your lawn. The first obviously kills everything, the second may have an impact but it is not detectable and in our arid area, more would be closer to the nitrate levels found where it rains.
To put this in perspective, if you used the same criteria of no net impact on all life and applied that to the land, we would not have been able to construct a single building or road in San Diego. Walking on your property could have more negative impact on animal life then what we are doing to the ocean.
The area that receives the plume 4.5 miles out at sea is not sensitive habitat like tide pools or even kelp beds but what seams like an endless expanse of sand bottom, that to the untrained person looks like it supports no life. If some of this very diluted (and sanitized) water should happen to get back to shore, it would be a benefit to the kelp beds. If you want more life in the ocean, and to support our fishing industry, the logical solution would be to build man made rock outcrops that would expand our kelp beds. These would then use the nitrates and offset any difference our treated water makes in the ocean.
October 8, 2009 at 3:37 p.m. ( permalink | suggest removal )