ILLINOIS POLLUTION CONTROL BOARD

June

14,

1972

DANVILLE SANITARY DISTRICT

4~PCB72—161

v.

ENVIRONMENTAL PROTECTION AGENCY

OPINION OF THE BOARD

 (BY RICHARD

3,

 KISSEL):

On April 16,

 1972,

 the Danville Sanitary

 District

 (“Danvi11e~’)

filed a variance petition with

 the Board requesting relief from para-

graphs

 I and

 2 of the Board order in Environmental Protection Agency v,

Danville Sanitary District, PCB 71-28,

 decided May

 26, 1971 and amended

August

13,

 1971.

 Paragraph

 1 of the Order required Danville to install

temporary sewage treatment facilities capable of adding sodium hydro-

xide and/or lime in order to continually adjust the pH of the raw wastes

between 9.0 and 9.5.

 Danville was to operate these facilities

 so as

to reduce effluent concentration of BOD5 to

 20 mg/l and of suspended

solids

to

50

 mg/I.

 Paragraph

 2 of the May

 26, 1971 Order prohibited

further sewer connections tributary to the Danville treatment facilities

until BOD5 effluent concentration was reduced to

 20 mg/i and suspended

solids concentration to

50

mg/i.

 On August

23,

 1971,

 the Board

author-

 ized hookups for an additional

 1500 population equivalents provided

that the effluent discharged from the plant to

the

Vermilion River

did not exceed 30 mg/i of BOD5 and 25 mg/i of suspended solids.

As regards relief from Paragraph

1,

Danville indicates that

it

will be able to produce a satisfactory effluent by means other than

the

sodium hydroxide or lime additions required by the Board.

The

Agency

has no objection to Paragraph

1

being rescinded so long as Danville’s

effluent meets the applicable state standards.

Since the imposition of the sewer ban, Danville has taken several

significant steps toward alleviating the BOD5 and the suspended solids

problems its plant faced.

 Danville sponsored an intensive examination

of its sewage treatment facilities

 in order to discover the reasons

its activated sludge process was not performing correctly.

 This exam-

ination showed a severe biological imbalance in the activated sludge

process.

 A new chlorination system was installed and anhydrous ammonia

was added to

the

waste stream in an attempt to correct the biological

imbalance.

 Danville also established industrial waste standards and a

surcharge ordinance in order to control the amount of industrial effluent

and to pay for necessary improvements to provide adequate treatment for

such wastes.

 Each affected industrial discharger has a time schedule

4

—

673

for compliance.

 In an attempt to combat the large sulfate concen-

ttati’ons coming into

the plant and upsetting the anaerobic digestion

process, Oanville has entered into

 a contract whereby the sulfate dis-

charger has provided Danville with an interim method of stimulating

anaerobic digestion in the presence of excessive sulfur concentrations;

by mid-1974, the sulfate discharger is

 to have installed its own pre-

treatment facilities.

 Most importantly, flanville has signifIcantly

reduced the concentration of BOD5 and suspended solids in its effluent.

For example, March, 1972 data showed monthly average BOD5 at 21 mg/i

and

suspended solids at 24 mg/i; for April, average 13OD~was 20 mg/I

and suspended solids,

 22 mg/i; for May, BOD5 averaged 19 mg/i and

suspended solids,

 15 mg/i.

 This performance is in compliance with

the standard set in the Board order in PCB#71-28.

 The plant

 is also

within the

SWB-9

standard of

20

mg/i,

 BO~5and 25 mg/I suspended solids

for activated sludge plants discharging to

the

Vermilion River.

The

plant is also successfully treating its

suspended solids,

 a significant

problem when Danville first appeared before the Board.

Based on data from the treatment plant through February,

 1972,

the

Agency recommended that the variance not be granted as

to

Paragraph

the sewer ban,

 until Danv~i1lehad shown ~~continuedsatisfactory operation

(of the treatment plant)

 for another month.~ With the data presently

received by

 the Board and accepted by the Agency as credible, the

operations through

Nay,

 1972 have, achieved that “continued satisfactory

operation” which the Agency sought.

 We also note that continued im-

provement in operation has been demonstrated.

 The conditions imposed

on Danville in Paragraphs

 I and 2 in PCB ~71-28 will,

 therefore,

be

rescinded.

 The grant of their petition, of course, does not release

Danville from its obligation to comply with the applicable state stan-

dard,

Over the past year, this Board and its

staff

have frequently

orally commended Danville for the remarkable progress and innovation

it has shown in the operation of

 its sewage treatment plant.

 We have

encouraged other Illinois municipalities and sanitary districts to

emulate Danville’s advances.

 We add such praise now in writing.

Danville’s positive response and affirmative action to abate its

pollution problems over the last recent months have heartened the Board

 that progress can be and is being made.

 It is also encouraging to see

local industry working with the sanitary district to solve their mutual

problems,

Danville Sanitary District is hereby released from the conditions

imposed by Paragraphs

 1 and

 in the Board order in PCB 71-28, May 26,

1971 as amended August 13, 1971,

I,

 Christan Moffett, Clerk of the Illinois Pollution Control Board,

certify that the aboi~~eOpinion was adopted on

 the 14th Day of June,

1972,

 by a vote of

to

~

4

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674