ILLINOIS POLLUTION CONTROL BOARD
June
6,
1975
ENVIRONMENTAL PROTECTION AGENCY,
)
Complainant,
V.
)
PCB 74-~351
WHEATON SANITARY DISTRICT,
a
Municipal Corporation,
)
Respondent.
Russel
R.
Eggert, Assistant Attorney General for Complainant;
David G. Mountcastle, appeared for Respondent.
This
is an enforcement action filed by the Environmental
Protection Agency
(Agency) on September 24, l974~ Respondent,
Wheaton Sanitary District
(Wheaton),
is charged with operating
its sewage treatment plant in such a manner as to emit odors
into the ambient atmosphere, said odors allegedly being
contaminants within the meaning of Section 3(d) of the
Environmental Protection Act
(Act)
Specifically, the
Complaint alleges that since on or about April
1, l974~and
continuing intermittently until the filing of the Complaint,
Respondett has caused or allowed the discharge of odors into
the environment so as to cause or tend to
c..ause air pollution,
either alone or in combinatibn with contaminants from other
sources,
in violation of Section
9(a)
of the Environmental
Protection Act~
The Wheaton Sanitary District owns and operates a
facility known as
the Wheaton Sanitary District Sewage
Treatment Plant,
(STP), which is located on Schaffner Road
approkimately one mile south of Roosevelt Road in Wheaton,
DuPage County, Illinois,
The
equipment at the STP includes two comminutors,
two
aerated grit channels, two raw sewage pump dry wells and
pumps, one Magnetic Flow Meter, ten primary clarifiers, two
high rate trickling filters
with
recirculation pumps, one
gas chlorinator with control building, three anaerobic
digesters
and
sludge drying beds having a total area
of
approximately 91,600 square feet,
The treatment plant
serves the entire city
of Wheaton
and certain
areas adjacent
to the City,
17
—
251
—2—
Hearings were held on November 21,
1974, November 22,
1974, December 18, 1974 and December 19,
1974.
The November
hearings were devoted primarily to the testimony given by
nineteen
(19)
citizens who told of their experiences with
the odors emanating from the Wheaton Sanitary District
Sewage Treatment Plant.
The Wheaton Sanitary District made
no effort to deny the odors, but emphasized the following:
1.
Odor detection or reaction is highly subjective.
2.
There is some odor emanating
front all sewage
plants unless all equipment is covered.
3.
Located in close proximity to the treatment plant
is the Streams, a residential subdivision.
All the
Complainants, but one,
live in the Streams.
The
treatment plant has been located on its present
site since at least the 1920’s while the Streams
development was started only several years ago.
The citizen witness described the odor as
“an untreated
outhouse”,
“manure”,
“a human excrement type odor
(R.7),
“sewer odor”
(R.32),
“dirty diaper pail”
(R.73).
There was
agreement among
the
witnesses that there was no odor prior
to about April
1,
1974 and that the odor was present downwind
from the plant continuously since then.
We find that the unanimity expressed by the citizen
witnesses with regard to the offensive nature of the odors,
the extent to which they were denied the use and enjoyment
of their properties, and the general agreement that the
odors started on or about April
1,
1974,
is not answered by
claims of subjective nature of odors, or existence of odors
at all times in sewage treatment plants.
We find the existence
of the odors over such a long period of time to be due to a
malfunction of the anaerobic digester which was not properly
investigated and remedied in the shortest possible time.
(Anaerobic digestion is
a biologic process in which waste
sewage sludge is changed by bacterial action into an innocuous
substance which is
stable, and no longer environmentally
offensive.)
Respondent ascribes the entire problem to sewage-borne
toxic metals that came into the plant during the third or
fourth week in March, 1974
(R.358,359,360).
It is asserted
that the heavy metals are particularly toxic to the methane
forming bacteria
(R.357) (R.433).
17
—
252
—3--
The breakdown of the offensive organic matorial causing
odors takes place in several stages.
Thc
finol stage of
digestion is the production of
methane by met~Lane
forming
bacteria.
These bacteria are partL~u1ar1ysensitive to
temperature, concentration of volatile acids, and toxic
metals
(copper,
zinc,
chromium).
If these bacteria die off
for some reason, the drawoff from the digester is no longer
inoffensive, but is likely to produce a severe odor problem
(R. 354,357,385).
An upset in the digestion process is responsible for
the development of odors when the digested sludge is drawn
off..
The Agency alleges, and has proven, that the digester
problem is due at least in part to District negligence and
cites the digester temperatures during January and February,
1974 to support its position.
An examination of the Operating
Report for January, 1974,
shows that starting
on January 23,
the digester temperatures fell below 90°. March digester
temperatures
fell as low as
510
F.
As
late as May,
the
temperature for the digester rose once to
710
F, with the
remaining days falling into the 50°-60°range
(Ex,8).
Since
the optimum temperature for digester operation is between
95°and 100°F,
(R.358),
there were apparently some problems
with the digesters before March.
Regretfully, the record
gives no indication as to the cause of these low temperatures,
in spite of the fact that enough digester gas was being
produced to do additional heating.
However, we cannot doubt that the massive failure exper-
ienced after March was caused by an influx of heavy metals.
The analysis made by the Agency on samples taken on July 11,
1974,
July 18, 1974 and July 22,
1974,
clearly show that
the digesters and primary clarifier contained considerable
amounts of heavy metals
(Resp.
Ex.
12).
We must take particular notice,
in examining Resp.
Ex.
12, that sheets dated 7—11-74, indicate that the holding
time in Digester #1 may have been drastically reduced from
the design holding time, due to a buildup of ash in the bottom
half of the digester.
17— 253
—4—
The sharp differences in solids and chromium concentrations
proves that very poor mixing took place in the digester.
The concentrations of about 20
and higher below the 12’
level clearly indicates a very strong likelihood that there
has been
a buildup for some time and that the reduction in
holding time may have been a major factor in causing digester
failure.
The importance of mixing and its relation to
holding time are both fully understood by Respondent
(R.38l,382)..
However,
it was
not until the mixing tube of Digester #2 was
found inoperative that this was acknowledged
(R,382).
We are convinced that a thorough study of the problem had
not been made and this’ may account for the extended time
over which it has existed.
We find that the Wheaton Sanitary District did in fact
operate its sewage treatment plant in a manner which caused
air pollution in violation of Section
9(a)
of the Act.
In reaching this conclusion, we have thoroughly considered
as we must
the reasonableness of the Wheatdn Sanitary
District’s odor emissions,
including the factors enumerated
in Section 33(c)
of the Environmental Protection Act,
I.
As our discussion above clearly shows, the character
of the emissions from the sewage treatment plant were such
as to seriously interfere with the normal enjoyment of life
and property, particularly insofar as those emissions affetted
the citizen witnesses who presented testimony at the hearings
in this matter~
2~
The social and economic value of a properly operated
sewage treatment plant need not be explained here,
But when
these plants are improperly operated,
as we have found was
the case here,
they in part lose their value; instead of
abatirg pollution,
as is their function, they in fact become
a pollut.ion source.
While the value of such pollution
source here is high if properly operated,
it is clear that
the sewage plant at issue here should not even have been
such a source.
17
—
254
—5—
3,
Insofar as the witness
testis~onyin this ma~~r
indicates that the sewage treatment plant did rot become
a
source of offensive odors until 1974,
the Wheaton Sanitary
District’s priority of location in the mbea involved dates
only from that time for purposes of
our: consideration here,
Therefore, despite the Wheaton Sanitar~’District’s protestations
to the contrary,
it does not
—
as a source
.
7 odors
—
have
priority of
location, even as regards the Sf
‘~‘
as development,
discussed above.
Further,
it is patent
tha..
as improperly
operated sewage treatment plant is unsthtable ±orany area;
by nature of our findings here,
we need not consider the
suitability of
a properly run plant for the ar~eain question.
4.
As is plain from the remainder of our Opinion and
Order,
it is eminently practical and reasonable to eliminate
the odor emissions here,
The plant merely need be run
right,
We shall not, however, impose a penalty in this case,
Respondent
has apparently made a considerable effort to abate its acknowledged
odor problem,
A cease and desist .order was issued after one sorice
of chrome was discovered through persistent searches of sewers
tributary to the treatment plant
(R,
368,
369).
Wheaton Sanitary
District made repeated efforts to dispose of the contaminated
sludge after the odor problem became intolerable
(R,
372,
373),
After the source of chrome was discovered
in October,
1974, and
eliminated, digester temperatures began
a return to the normal
range, and the pH imbalance has been partially corrected
(R.
380).
Normal operation was expected within a few months
(R.
441).
In
addition, improvements are being made at the plant with the expec~
tation of meetin~all requirements
CR,
442),
For these reasons,
we feel that it would serve no purpose to impose a civil penalty in
this case,
We therefore order the District to cease, and desist
from operating its plant in such a manner as to emit odors
into the ambient atmosphere, which constitute air pollution
in violation of Section 9(a)
of the Act;
and to make a
careful and detailed study of the causes of the failure to
continually produce a digester drawoff which is not offensive,
as had been done prior to April,
1974.
We order Respondent
to report the results of this study to the Agency within 90
days of the date of this Order, and to submit a plan of
action which could be put
into
effect
if there should be a
repetition
of
the
odor
problems.
This
Opinion
constitutes
the
Board’s
finding
of fact
and conclusions of law,
17
—255
—6—
ORDER
IT IS THE ORDER of the Pollution Control Board that Respondent
Wheaton Sanitary District cease and desist from operating
its Sewage Treatment Plant in violation of Section
9(a)
of
the Environmental Protection Act, subject to the following
conditions:
1,
Respondent shall make a thorough study of the
causes and aggravating factors of digester failure and
report the results to the Environmental Protection Agency
within
90 days of the date ofthis Order.
2.
Within 90 days of the date of this Order Respondent
shall submit to the Environmental Protection Agency a plan
of action to be put into
effect
if there should be a recurrence
of digester failure.
I, Christan
L.
Moffett,
Clerk of the Illinois Pollution
Control Board hereby certify that the above
Order were adopted ~n the ~~~day
of
l975byavoteof~to
o
ILLINOIS
POLLUTION
BOARD
17
—
256