TM 58138
y 235.3
z [124,400  28.8(235.3)]/398.8
z 295
x 500  235.3  295 = 30.3
but the Total Dissolved Solids in this corner is:
?
30.3(95.5) + 235.3(851) + 295(729) 250,000
412,401.65 250,000
Therefore, this corner is outside of the TDS constraint. See figure A22 point F.
b. Total Dissolved Solids  Chloride Pair
Total Dissolved Solids 755.5y + 633.5z 202,250

(633.5/20)Cl = 14,253.75y  633.5z 3,167,500
15,009.25y 3,369,750
y 224.5
z [202,250  755.5(224.5)]/633.5
z 51.5
x 500  224.5  51.5 = 224
=
and for Sulfate SO4 ;
?
224(1.2) + 224.5(30) + 51.5(400) 125,000
27,603.8 125,000
Therefore, this blend will have less than the maximum allowable sulfate concentration.
c. Total Dissolved Solids  Sulfate Pair
Total Dissolved Solids 755.5y 202,250  633.5z
=
755.5y 3,263,340.3  10461.6z
(755.5/28.8) SO4 =
∴solving for the equal condition only
202,250  633.5z = 3,263,340.3  10,461.6z
z = 311.5
y [202,250  633.5(311.5)]/755.5
y 6.5
using the equal condition makes z 311.5
x 500  311.5  6.5 = 182

and for chloride Cl
182(50.0) + 6.5(500) + 311.5(30) 125,000
21,695 125,000
Therefore, this blend will have less than the maximum allowable chloride C1 concentration.
Blends containing only high quality secondstage product water and one of the remaining waters x or y could be
most economical.
d. Well Water z and Water x
1. Sulfate limited
z 500 (250  1.2)/(400  1.2)
z 311.9 so x 188.1
2. TDS limited
z 500(500  95.5)/729  95.5)
z 319.25 so x 180.75
3. Chloride cannot limit since both have chlorides below 250.
e. SinglePass Reverse Osmosis Water y and Water x.
A36