September 18, 2012

PHOSPHORUS CHALLENGE & ECONOMICS


 ● A huge STA for removing P
The main problem for Florida Everglades is phosphorus contamination.  Huge tracts of land for constructed STAs are required for its removal. That is a very expensive water treatment indeed – paid for mainly by the taxpayers. While economical P-removal requires a technological breakthrough, some alternative ideas may be worth examining. A little summary can get us started:
- we have P-contaminated waters;
- we need to keep using big water quantities AND phosphorus for agriculture (it is NOT going to go away any time soon);
- that agriculture needs water - and keeps pumping and using perfectly CLEAN water from underground aquifers – only to contaminate it with hard-to-remove phosphorus.
● Water with plenty of P in it – use it.
Obviously, the agriculture needs WATER and P.
Give and distribute it to them already in a MIXTURE - and :
- save ourselves huge costs of removing P from water (to required low levels of 10 ppb for the Everglades);
- preserve the precious clean aquifers;
- recycle the finite phosphorus resource.
In other words - why don't we have agriculture using exclusively P-loaded water instead ?
Of course, that would mean -
- gathering and holding that water;
- pumping that water;
- conveying that water (higher-tech distribution PIPELINES rather than canals ?);
- have somebody (user ?) pay some (?) of the water conveyance costs.
The clincher of such a scheme is that this approach may still be CHEAPER than buying out LAND for, constructing and operating STAs. Some specialized reservoirs would still be needed but definitely no back-pumping of P-polluted water that further spoils LO.
Particularly considering that (and how) the whole regional water scheme will radically change with the disallowing and discontinuation of ocean outfalls - in a not too distant future.
It may also be worth noticing that, over the past century, Lake Okeechobee and its muds have become a veritable repository of phosphorus. 
● Phosphate mining in Morocco
The finite nature of world phosphorus supply (Morocco) leads us to the necessity of exploiting even low-level sources of the element so essential for agriculture.  High-phosphorus muds of Lake Okeechobee really represent a resource.
All these considerations should become another serious ELEMENT  in the water management schemes for Central and South Florida  (among those others like BMPs, RASTAs, LO, etc.).
Naive ? - well, keep it in mind and just see somebody else coming up with it sooner or later.