P-RICH WATER for AGRI

The rumination and idea outlined here may be somewhat raw and only semi-baked. But the more we think of it the more we get the drift of it – and it looks quite logical.  It has to do with Central and South Florida watershed schemes and Phosphorus removal.  At this point, nobody doubts that phosphorus contamination is the main culprit in deterioration of what’s left of the Everglades.

 

These huge-scale ecological systems have to be approached like one HUGE scheme, not so much piece-meal.  The northern watersheds dump nutrients into Lake Okeechobee – that, in turn, has to release its waters further downstream.  We cannot expect these waters to be clean because Lake Okeechobee is thoroughly overwhelmed receiving 500-600t of P/y (max. 105 tP/y allowed).

The South of the Lake, Everglades Agricultural Area, with its vast sugar-cane monoculture, makes the nutrient surplus situation even worse.  A series of new STAs are valiantly struggling with the nutrient (mainly phosphorus) overloads that impair their performance in cleaning up water destined to eventually feed the Everglades Protection Area and the ENP itself.  According to the latest calculations, new expanses of land are now required for expansion of STAs and water reservoirs (FEBs). The latter are necessary for water storage and smoothing the seasonal flood and drought situations.

It is necessary to emphasize that these man-made water storage and cleansing structures are built and operated on taxpayers money.  We shall let the stakeholders argue about this concept, keeping the Tallahassee lobbyists busy (and paid).  

In summarizing the situation, it can be said that -

- we have huge quantities of P-contaminated waters representing a problem;
- large quantities of fresh water AND Phosphorus are used for agriculture operations (NOT going to go away any time soon);
- agriculture needs water - and keeps pumping and using perfectly CLEAN water from underground aquifers – only to contaminate it with hard-to-remove phosphorus.
It is clear that the agriculture needs WATER and P. 
Why not give and distribute both to them already in a MIXTURE ! - and -
- save huge costs of removing P from water (to extremely low levels of 10ppb), and
- preserve the precious clean fresh-water aquifers for city use.

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 – perhaps using modern higher-tech distribution PIPELINES rather than canals that suffer from seepage and high evapotranspiration losses;
- have somebody (user ?) pay some (?) of the water conveyance costs.

One could go even one step further, realizing that : 

- As surplus P-rich water from Lake Okeechobee (LO) is currently relased ‘to the tide’ (Caloosahatchee and St. Lucie Rivers) it wreaks havoc along these waterways and on the estuaries. 
- The shallow muds in LO contain high amounts of deposited “legacy” Phosphorus accumulation.
- Large land areas in the EAA suffered soil oxidation, depletion and subsidence (5 feet at some locations).
- The key to water quality and quantity problems in Central and South Florida is Lake Okeechobee.

Pumping out P-rich muds of LO

This may perhaps be a longer range challenge –filling in badly subsided and eroded sections of EAA land, enriching and building up the soil. This approach would be helpful in solving numerous existing side-problems. This may be the only way of solving the LO outstanding water quality problem that stands out and has not even been addressed to this day. Too big a chunk to swallow ?

In fresh water we have what is rapidly becoming a diminishing resource. Just like our municipal water distribution structure is rapidly becoming duplicated – for fresh water and for recycled water, we can expect a similar concept used for agricultural irrigation:  use P-loaded water for that purpose.

Now - here is the economics clincher:
This approach may still be CHEAPER than buying out LAND for and operating FEB-STAs combinations. Nedless to say, with Florida dry-wet seasons, water-storing reservoirs will always be needed.

The whole regional water scheme will likely radically change also with the blocking of remaining ocean outfalls - in a not too distant future. A dual water distribution network is quickly becoming commonplace with those purple 'recycle water' pipelines being laid down everywhere.

The water-phosphorus-agri scheme discussed here should become another ELEMENT in the water management puzzle of Central and South Florida - among all those others introduced, like BMPs, RASTAs, LO, dispersed water storage, etc. 
Not one, not two, but ALL of these remedial actions need to be applied in concert since there is no silver bullet of a solution for problems of this magnitude, compounded by a century of wrong and neglect.
Enough -
That's MY five-billion-dollar conceptual suggestion - for consideration and to keep on the drawing board of solutions being suggested, examined, and eventually pursued. 
Examine it. We just have to better look after our water resources.
Naive ? - well, keep it in mind and just see somebody else coming up with it sooner or later.