You might check out the Ultra-Sun (I think the name has changed to  Sun-Pure) 
            under-the-sink water filter, for around $300.  This is said to 
remove all  bacteria through the use of ultraviolet light.  It also has a large 
filter,  which probably would remove parasites (be sure to inquire about 
this).  I  bought this type of filter for my husband's house, my house, and my 
daughter's  house, and we have had excellent results with these.  My daughter 
and  
husband live in Los Angeles, and you can imagine how bad the water is out  
there!  I remember the company advertised that you could take sewer water,  
process it through this unit, and it would be drinkable.  There are a few  
chemicals which will pass through the filter; you need to inquire about its  
limitations (I believe nitrates will pass through).  The last number I had  for 
Ultra-Sun Technologies was 909 (may be 951 now) 808-1992, and I purchased  the 
units 
from Nature's Distributors, Inc., (800) 624-7114.
 
I presently have a ranch in a rural setting (77 acres).  The nursery  next 
door must use pesticides and nonorganic fertilizers, not to mention rodent  
poison, and so forth.  We have a well.  I have a Sun-Pure filter at my  kitchen 
sink, but in addition I have installed a "nanofilter" because of the  
excessively hard water from the well which makes using the steam bath,  
dishwasher and 
water distiller impossible.  This nanofilter takes the parts  per million of 
the water from 16,000 to 22,000 down to 16 parts per  million.  In essence, it 
is very near distilled.  I had the Best  Technology Company which sold me the 
unit install a valve to let a little more  of the dissolved solids into the 
water, as I don't think it is healthy to drink  distilled water on a long-term 
basis.  This system will run around $12,000,  however, and underground outdoor 
plumbing could be required, in addition,  depending on your setup.  If you are 
interested in this second option  (which would remove virtually everything 
from the water), you can contact David  at Best Technology Company at (909) 
841-8083.  He can give you his web  site.
 
If I were in your shoes I would contact an excellent psychic to find out  
before spending a lot of money where your problems are coming from, and which  
remedies would be effective.  I have found an excellent psychic I use for  many 
situations, and have never been disappointed.  He is very affordable  and 
motived to serve rather than line his pockets.  You can contact Johnnie  
Psychic 
Advisor at _www.Keen.com_ (http://www.Keen.com) .  His  extension is 0183247.
 
I have three wells, and as part of the permitting process, was required to  
pass county tests for bacteria.  We treated all three with the Chlorox  method 
another list member described.  However, I don't know how long it  would be 
before bacteria could return.  With the Ultra-Sun and the  nanofilter, though, 
I 
don't need to worry about it.
 
Hope this helps,
 
Jill