ILLINOIS POLLUTION CONTROL BOARD
March 17,
1977
IN THE MATTER OF
TOTAL DISSOLVED SOLIDS
)
R75-6
EFFLUENT STANDARD
OPINION OF THE BOARD
(by Mr.
Dumelle):
A petition for regulatory change was filed by the Village of
Sauget on March 27,
1975, proposing amendment to Rule 408(b)
of
Chapter
3, Water Pollution Regulations.
This Rule sets forth the
effluent standard for total dissolved solids.
Accompanying the
proposal was
a petition with 200 signatures.
The proposal was published
in Environmental Register #101,
and hearings were held on September 23,
1975 in Sauget and
October
3, 1975 in Chicago to receive testimony and comments
regarding the proposal.
An Economic Impact Study
(IIEQ Docu-
ment No.
76/17) was submitted to the Board by the Institute On
August 24,
1976 pursuant to Section
6 of the Act.
Hearings to
receive comments on this study
(Exhibit 19)
were held on November
3,
1976 in Chicago and December 17, 1976 in Peoria.
All testimony,
exhibits, and public comments included in the record of this
proceeding have been considered by the Board in rendering a
Uecision on the proposed regulation.
The effluent standard in
Rule
408(b)
requires that total
dissolved solids
in an effluent shall not increase more than 750 mg/i
above background concentration levels unless caused by recycling
or other pollution abatement practices, and at no time may
they exceed a concentration of 3500 mg/i.
This standard is
discussed in the Board Opinion of January
6, 1972
(R70-8, R71-14,
R71—20)
,
supporting the effluent regulations.
The proposal presented by the Village of Sauget in this
proceeding R75—6
is to exempt from the total dissolved solids
effluent standard those sources that meet water quality standards
for total dissolved solids in receiving waters to which they
discharge.
The argument stated in the petition and discussed
further in testimony is that, although the technology
is available
to meet the effluent standards, such treatment is economically
unreasonable.
The petitioner also stated that the present
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effluent standard discourages the use of water recycling techni-
ques, because recycling results
in increased concentrations of
total dissolved solids
in a smaller volume of effluent, which
may then violate the standard.
At the first hearing the petitioner requested that the
original proposal be
limited to apply only to discharges to the
Mississippi River.
The testimony was limited to the Village
of Sauget treatment plant operation, the costs required for Sauget to
install and operate treatment facilities
to meet the present
effluent standard,
and the impact of the Sauget treatment plant
total dissolved solids discharges on the water quality in the
Mississippi River.
Sauget Wastewater Treatment Plant
At the time of the hearings in 1975 the Sauget plant
provided primary treatment to approximately 15 million gallons
per day
(MGD)
of waste stream, average dry weather flow.
The
wastes treated are 99
industrial wastes from companies in
Sauget.
The waste stream had been steadily reduced from a
1961 volume of
38 MGD, and the industrial dischargers were
committed to reducing flow to
8 MGD in 1976.
The reason for the flow reduction was to concentrate
the wastes in the stream to make
it easier to treat as well
as to reduce costs for construction and operation of a new treatment
facility.
Such a facility was under construction at the Sauget
plant in 1975, designed to provide secondary treatment by
means of chemical waste treatment.
The process includes
lime neutralization followed by precipitation of metals through
addition of polyelectrolyte and removal by sedimentation and
filtration.
This plant will discharge to the Mississippi River
until a Metro East area regional treatment facility is completed,
at which time it will discharge to that larger facility.
In 1975 the Sauget treatment plant effluent contained
3500-5500 mg/i total dissolved solids
(Exhibit 5).
The
effluent from the new secondary treatment facility
is expected
to have
a concentration of
8000 ppm, without any actual increase
in dissolved solids loading from industrial wastes.
The increased
concentration will result from flow reduction plus a contribution
of 700-1000 mg/i from lime added during neutralization.
The pro-
jected total dissolved solids concentration in the discharge from
the Metro East regional facility will be 3800 mg/i.
Therefore none
of the effluents will meet the 3500 mg/i standard.
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—3—
It
is noted that the Village of Sauget’s total dissolved sglids
measurements are obtained using an evaporation procedure at 103 C
(R.
30)
,
whereas
the Agency uses a procedure which evaporates
at 180°C (R.
236).
The procedure used by Sauget will result
in higher values,
as much as
50
higher according to the
Agency
(F.
222)
,
because organics and water of hydration and
occlusion will be retained in the residue which at the higher
temperature would evaporate.
A representative of Sauget testified that an Illinois
EPA computer printout of source effluent data for 1972 through
1974 showed that the Sauget plant was the only discharger
to the
Mississippi River in violation of the standard
(R.
47).
The Agency
could not verify which measurement procedure was used to obtain
that data.
There appears therefore to be some ambiguity
in the
effluent data presented in the record and in the present status
of Sauqet regarding compliance with the effluent standard.
However,
when its secondary treatment plant is completed,
its 8000 mg/i
effluent will clearly be in violation of the standard, regardless
of the measurement method used.
Availability and Cost of Treatment Technolo~
Four treatment processes are considered to be available to
remove total dissolved solids from wastewater.
These are reverse
osmosis, electrodialysis, distillation, and ion exchange. The
processes are described briefly on pages 4—6 of Exhibit
1,
and Dr. James Patterson also described them in his testimony
(F.
109-113).
All four processes
remove solids from the waste
stream and concentrate them in a brine stream, which must be
retreated or disposed of in an environmentally sound manner.
The capital and operating costs involved with each of the
four processes demonstrate that reverse osmosis
is the most economical
process, and
it is also the smallest consumer of energy
(F.
115—
118;
Exhibit
10, Table
1).
Dr. Patterson, consultant to Sauget,
considered
it to “represent a potential feasible process”
(R.
123).
There are several interferences which can affect the reverse
osmosis process, which thereby limit its applicability and
increase
its
COStS.
Reverse osmosis
is susceptible
to orqanic
material
in the wastewater which fouls the membranes,
as well
as to bacteria which degrade the membranes.
Also, when the
brine produced by the process becomes saturated with salts,
they will precipitate on the membranes,
causing irreparable damage.
The first interferences require pretreatment of the wastewater
with activated carbon, adding to the total costs.
The second
one limits the amount of concentration of salts and requires
careful control of the system to prevent precipitation
(F.
123-
125)
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165
—4—
The flow diagram in Exhibit 11 is
a conceptual design of
the reverse osmosis process which would be needed to treat
the Sauget secondary treatment plant effluent to meet the
3500 mg/i standard.
Only 5.6 MGD
(69)
of the 8.11 MGD flow
is treated, resulting in 1.41 MGD brine stream as waste and
4.19 MGD treated effluent which, when mixed with the remaining
2.51 MGD
(31)
of secondary effluent will yield a 6.7
MGD
discharge which meets the required 3500 mg/i total dissolved
solids.
Pretreatment prior to reverse osmosis includes filtra-
tion, pH adjustment,
softening,
and carbon adsorption.
Total
costs for the complete process, including waste
brine disposal by deep well injection, were estimated to be
$7.72 million capital and 5l.8~per 1000 gallon operating
costs
(Exhibit 10, Table
9).
These figures represent an
87.9
increase in total capital cost and 157
increase in
total operating costs for the new chemical treatment plant
(F.
144).
The cost estimates in the Economic Impact Study
(Exhibit 19)
included the $7.72 million capital cost, but
annual operating costs
of $1.74 million
(or 58.8’~per 1000
gallon) were utilized instead of the Village of Sauget estimates.
This higher estimate includes annualized capital cost as well
as fuel consumption and labor.
These costs for reverse osmosis
with deep well injection for brine disposal were compared to
costs anticipated using two other brine disposal methods.
Treatment
with deep well injection is shown to be by far the most economical
method,
though very expensive and possibly not an environmentally
acceptable one.
Impact of Sauget Effluent on Mississippi River Water Quality
Water samples taken in 1974 from the Mississippi River
just downstream from the Sauget outfall showed a maximum con-
centration of
368 mg/i total dissolved solids and a low reading
of 324 mg/i
(Exhibit 6)
.
Samples taken in 1975, also close
to
and. downstream from the outfall, yielded a high value of
397 mg/i and a low of 262 mg/i.
All of these values are well
below the applicable water quality standard of 500 mg/i for
water supply and
food processing waters.
Discharge from the new secondary treatment plant will
have little or no effect on concentrations in the river, because
the industrial waste loadings of dissolved solids will remain
the same,
though concentrated in a smaller waste stream.
The
only increase will be from the lime added during neutralization.
If, on the other hand, these wastes were treated
to meet the
3500 mg/i effluent standard, the improvement in river water
quality was estimated to be only
1 mg/i total dissolved solids
(Exhibit 19 p.
121),
reflecting the relatively small contribu-
tion of this plant to total loadings in the Mississippi River.
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Economic Impact of the Regulation
Costs
to Sauget calculated in the benefit cost analysis,
as
cited above, were $1.74 million per year for reverse osmosis
with
deep well injection of brine wastes,
to meet the standard.
These
costs were allocated to the industries discharging into
the treatment plant,
and their economic response to their increased
cost burden was predicted.
The response involved a potential
loss
of 0-652
jobs and possible price increases for their products of
0—1.3.
Long term loss of industry to the area was also pro-
jected as
a possible outcome.
The total benefits resulting from a
1 mg/i improvement in
dissolved solids water quality in the Mississippi River were
estimated to be $460 per year, resulting from reduction in
corrosion damage to power—generating cooling systems and to
residential household plumbing fixtures and appliances.
The
dissolved solids properties considered in the analysis were
corrosiveness, effects on osmotic pressure, and hardness.
Toxicity of individual constituents was not included.
This
regulation will have a slight economic impact on the people
in Illinois using Mississippi River water, but the impacts
resulting from compliance by Sauget with the effluent standard
are found
to be greater.
Because the Village of Sauget
is at this time the only
discharger to the Mississippi in violation of the effluent
standard,
exempting sources on that river from the standard
will result in minimal water quality impacts, as discussed
above.
Sources expected to exceed the 3500 mg/i level would
be
industrial processes discharging directly or plants such
as
the one
in Sauget which treat wastewaters primarily from
industrial operations.
The water recycling efforts of such
sources, both for resource conservation and to allow more
effective treatment of hazardous waste constituents, are relevant
considerations
in this matter.
When evaluated along with the
costs
to Sauget and environmental problems involved with treating
total dissolved solids,
as well as the minimal expected impacts
on users of the Mississippi River, an exemption from the effluent
standard is merited as long as the water quality standard for
total dissolved solids
is
met.
We are not satisfied, however, that there is enough
information
in the record on the remaining waters of the State
to apply the amendment statewide.
Dilution ratios and background
dissolved solids concentrations vary widely for different receiving
waters, which may affect the relative water quality impacts
of
individual point sources discharging into them.
Discharge character-
istics and control capabilities of those sources may also be relevant.
Data presented for a number of rivers
in Illinois
show that
some
violations of the water quality standard already exist and that
concentrations of total dissolved solids are increasing slowly
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over time
in the Mississippi and Illinois Rivers.
These facts
must be considered thoroughly before a statewide exemption could
be allowed.
A proposal to delete the total dissolved solids effluent
standard from the
Water Pollution Regulations
is pending before
the Board
in R76-2l Effluent Standards Revision.
Further considera-
tion of
the standard and submission of additional information
regarding
its merits will be possible in R76-2l, and the record
of this proceeding R75-6 can be incorporated into the R76-2l
record.
Therefore,
at this time an exemption from the effluent
standard is allowed only for sources on the Mississippi River,
while leaving open the proposal in R76-21 for continued delibera-
tion on the merits of the statewide effluent standard for total
dissolved solids.
This Opinion constitutes the Board’s findings of fact
and conclusions of
law.
I,
Christan L. Moffett, Clerk of the
Illinois Pollution Control
Board, hereby certify the above Opinion w~sadopted
on
t-he
/7~day
of March,
I
971
by
d
voLe
of
____________________________
Christan L. Moffett,
rk
Illinois Pollution C
rol Board
25