^m.  Jour.  Pliarru.  t 
December,  1904.  j 
Purification  of  Water  Supplies. 
557 
vincing  to  give  you  briefly  the  results  of  the  treatments  of  a  very 
few  of  a  considerable  number  of  water  supplies  which  have  either 
been  treated  under  our  direction  or  as  a  result  ot  the  experiments 
and  information  given  out  by  the  Department  of  Agriculture. 
In  June,  1903,  our  attention  was  called  to  the  condition  of  the 
reservoir  at  Winchester,  Ky.  This  supply  was  constructed  in  1890, 
and  after  the  first  three  years  a  strong  odor  and  taste  was  notice- 
able in  the  water  during  the  hot  summer  months.  This  condition 
gradually  increased  until  the  water  attained  such  a  degree  of  offen- 
siveness  as  to  make  its  use  for  any  purpose  almost  intolerable. 
Aeration  and  mechanical  filtration  were  tried  without  effect,  and  it 
seemed  that  the  only  hope  for  relief  was  to  abandon  the  entire 
reservoir  and  go  ten  miles  to  the  Kentucky  River  for  the  source  of  a 
new  supply.  The  cost,  however,  was  too  great  to  be  considered, 
and  for  this  reason  the  difficulty  was  considerably  increased.  A 
microscopical  examination  of  the  water  showed  that  the  odor  and 
taste  was  due  to  the  presence  of  one  of  the  blue-green  algae,  and  it 
was  believed  that  the  application  of  copper  sulphate  at  the  rate  of 
about  I  to  5,000,000  would  be  sufficient  to  destroy  these  forms;  con- 
sequently, there  being  no  objection  on  the  part  of  either  the  water 
board  or  the  health  authorities,  a  treatment  was  made,  and  the 
results  have  been  everything  that  could  be  desired.  Within  three 
or  four  days  the  odor  disappeared  and  the  water  was  perfectly  clear. 
This  summer  at  about  the  same  time  it  was  feared  that  the  algal 
growth  was  reappearing,  and  for  this  reason  another  slight  treat- 
ment was  made,  but  with  this  exception  no  copper  has  been  added 
to  the  water  since  the  original  treatment  in  June,  1903,  and  it  has 
remained  perfectly  clean  and  sweet. 
In  1892  the  Butte  (Mont.)  City  Water  Company  began  the  con- 
struction of  a  large  impounding  reservoir  for  the  purpose  of  storing 
the  water  of  a  mountain  stream,  having  its  source  in  the  summit  of  the 
Rocky  Mountains.  The  next  year  the  stored  water  became  badly 
contaminated  and  was  unfit  for  domestic  use  on  account  of  its  dis- 
agreeable odor  and  taste.  In  1894  the  dam  was  increased  so  that 
the  capacity  of  the  reservoir  was  180,000,000  gallons,  but  the  same 
trouble  was  experienced  as  during  the  previous  year,  and  further 
work  was  stopped  on  the  dam  until  some  remedy  could  be  discov- 
ered. An  extensive  study  of  the  conditions  to  discover  the  cause 
and  find  a  remedy  for  the  trouble  was  undertaken,  and,  besides  a 
