Iowa Department of Natural Resources
Environmental Protection Commission

 

 

ITEM 17 Decision

 

 

 

Notice of Intended Action Chapter 61 Water Quality Standards (Updates

TOPIC to Wasteload Allocation Procedure and E. Coli criteria)

 

There are two primary purposes of this proposed rule. The ?rst is to revise the rule referenced
document ?Supporting Document for Iowa Water Quality Management Plans.? This document
was last updated in 2009. It establishes the technical methodologies the DNR uses to develop
wastewater permit limits based on water quality criteria. The proposed revision will provide
more ?exibility for facilities seeking to use alternative permitting options. For example, the
revision will allow the use of stream low flows in addition to annual stream low flows,
alternative methodologies for deriving site?speci?c permit limits, and fewer sampling
requirements for site-speci?c data collection. These changes will result in cost savings for
permitth facilities. The proposed revision will also clarify and update the procedures the DNR
uses to calculate permit limits based on water quality criteria and will ensure those procedures
make use of the most recent scientific data. The proposed revision. also changes the title of the
document to more clearly re?ect its contents. The revised document will be titled ?Iowa
Wasteload Allocation (WLA) Procedure.? The current and revised versions of the document are
available on the website at 
Quaiity/Wasteload-Allocations.

The second purpose of this proposed rule is to update the water quality criteria for E. coli by
eliminating the existing single sample maximum value. The DNR has determined that the single
sample maximum value is overly stringent and is not an appropriate tool for water quality
assessment and permitting purposes. The geometric mean E. Coli value will be retained as it is
the more appropriate measure and is protective of recreational activity in Iowa?s waters. This
change will result in fewer water bodies being listed as impaired by the overly stringent single
sample maximum E. 0011' value.

Jon Tack, Chief
Water Quality Bureau
Environmental Services Division

 

ENVIRONIVIENTAL PROTECTION 

Notice of Intended Action

Pursuant to the authority of Iowa Code sections '1 I) and 45531739) and
(3), the Environmental Protection Commission (Commission) hereby gives Notice of Intended
Action to amend 567 Iowa Administrative Code chapter 61, ?Water Quality Standards,? and

chapter 62 ?Effluent and Pretreatment Standards: Other Effluent Limitations or Prohibitions?.

The purpose of the proposed amendments is to:

l. Revise the bacteria water quality criteria table at 567 IAC 61.3(3) The
revision will eliminate the single sample maximum values of235 organisms per 100 milliliters of
water for Recreational Use Classes A1 and A3 and 2,880 organisms per "100 milliliters of water
for Recreational Use Class A2. The Commission has determined that the single sample
maximum value is overly stringent and is not an appropriate tool for water quality assessment
and permitting purposes. The geometric mean E. coli criterion is a more appropriate measure

and will be retained.

2. Update the rule referenced document ?Supporting Document for Iowa Water Quality
Management Plans, Chapter IV, July 1976, as revised on November I I, 2009.? The revision of
this document will include a title change to ?Iowa Wasteload Allocation (WLA) Procedure? to
more clearly reflect the contents of the document. A wasteload allocation (WLA) is the portion
of a water body?s assimilative capacity that is allocated to an existing or future point source
discharge. This document establishes the technical methodologies the Department of Natural
Resources (Department) uses to develop WLAs and water quality-based effluent limits for point

source dischargers. The revision will make the document more understandable and better

 

describe the procedures used in WLA calculations. The update will also provide greater

?exibility to facilities seeking alternative permitting options.
The major elements of the Iowa WLA Procedure document revision are as follows:

a. Update the Stream Low Flow Values for United States Geological Survey (USGS)
gaged sites and ungaged sites based on the USGS low flow study report ?Methods for Estimating
Selected Low?Flow Frequency Statistics and Harmonic Mean Flows for Streams in Iowa,? by
David A. Eash and Kimberlee K. Barnes, published in 2012 and revised in 2013. This change
will incorporate the most stream critical low flows published by USGS to better

reflect actual stream low flows;

b. Incorporate statewide default background chemical concentrations using the most up?

to-date monitoring data available;

0. Incorporate statewide default ef?uent chemical concentrations for different types of

wastewater treatment plants using the most up-to-date ef?uent monitoring data available;

(1. Replace the total residual chlorine default decay value in the mixing zone with site-

speci?c decay measurements;

e. Incorporate the current implementation procedures for the chloride and sulfate criteria

that were adopted in 2009;

f. Revise the E. (20117 WLA procedures for both continuous and non?continuous discharges

to re?ect the E. (2013' criteria changes at 567 IAC 61.3(3) as described above;

g. Revise the E. coli decay rate coef?cient to be consistent with other Department

programs;

 

h. Revise the temperature criteria implementation procedure to incorporate all elements
of the temperature criteria in 567 IAC chapter 6] for different designated uses. The proposed
revision to the temperature implementation procedure provides ?exibility for facilities seeking

alternative permitting options;

i. Modify the WLA procedure for pH so that pH criteria must be met at the boundary of
the mixing zone instead of the boundary of the zone of initial dilution. This will result in

increased dilution for pH WLA calculations;

j. Clarify that the fathead minnow is to be used as the most sensitive representative

species for establishing acute toxicity ef?uent limits for general use waterbodies;

k. Clarify the current mixing zone procedures and the requirements for mixing zone and

diffuser studies;

1. Incorporate a Site?Speci?c Data Collection Procedure in order to standardize the site?
speci?c data collection process. The pr0posed revision will have fewer sampling requirements
and will result in cost savings for point source discharge facilities seeking site-speci?c permit

limits;

m. Revise the Water Quality Modeling section to replace previous models with
commonly used and modernized and Modi?ed Streeter-Phelps models. It will also

update decay rates and reaeration rates to reflect the latest scientific data;

n. Add a reference to the antidegradation implementation procedure document;

 

0. Add a new section on Alternative Site-Speci?c Methodology for Water Quality Based
Limits that provides point source discharge facilities with the ?exibility to develop site speci?c

NPDES permit limits.

Other minor revisions to the document include improvements in the estimation of
ammonia nitrogen decay calculations in discharge pipes and general use segments, clarification
of the procedure for determining discharge flows used in WLAs, and clarification of various
sections to make the document more understandable. The proposed ?Iowa Wasteload Allocation
(WLA) Procedure? document is available at 


The proposed amendments also update references to the Department?s website.

Any person may submit written suggestions or comments on the proposed amendments
through September 8, 2017. Such written material should be submitted to Connie Dou, Water
Quality Monitoring and Assessment Section, Iowa Department of Natural Resources, 502 East
9tln Street, Des Moines, Iowa 50319-0034, fax (515)725-8202; or e?mailed to
Connie.Dou@dnr.iowa.gov. Persons who have questions may contact Connie Dou by e-mail or

by telephone at (515)725-8400.

Persons are invited to present oral or written comments at a series of public hearings,

which will be held throughout the state as follows:

Date Time Location

September 5, 2017 4:00 pm State Bank Room
Washington Public Library
1 15 West Washington St.
Washington, IA

 

September 6, 2017 4:00 pm Meeting Room 

Urbandale Public Library
3520 86?? St.
Urbandale, IA

September 7, 2017 4:00 pm Harlan Community Library
718 Court St.

Harlan, IA
Persons attending a hearing will be asked to give their names and addresses for the record

and to con?ne their remarks to the content of the proposed amendments.

Any person who intends to attend a public hearing and has special requirements, such as
those related to mobility or hearing impairments, should contact the Department to advise of any

speci?c needs.

After analysis and review of this rule making, these amendments are expected to have a
positive impact on jobs. The amendments are projected to result in a total cost savings for cities,
industries, and semi?public entities ranging between $26 million and $58 million. This total
savings is expected to be achieved by approximately 94 facilities across the state. These cost

savings will likely lead to further investment in production and job growth.

The proposed amendments are intended to implement Iowa Code sections 4558.1 05(1 1)

and 45531730) and (3).

The following amendments are proposed.

 

ITEM 1. Amend paragraph 612(4) as follows:

a. Due to extreme variations in wastewater and receiving water characteristics, spatial
dimensions of mixing zones shall be de?ned on a site-speci?c basis. These rules are not
intended to de?ne each individual mixing zone, but will set maximum limits which will

satisfy most biological, chemical, physical and radiological considerations in de?ning a

particular mixing zone. Additional details are noted in the 

 

?1099g ?lowa Wasteload Allocation (WLA) Procedure,? [effective date], for considering unusual

site?speci?c features such as side channels and sand bars which may in?uence a mixing zone.
Applications for operation permits under 567?subrule 64.3(1) may be required to provide
speci?c information related to the mixing zone characteristics below their outfall so that

mixing zone boundaries can be determined.

ITEM 2. Amend paragraph 612(4) introductory paragraph, as follows:

I). For parameters included in Table 1 only (which does not include ammonia

nitrogen), the dimensions of the mixing zone and the zone of initial dilution will be calculated

using a mathematical model presented in the 

?Iowa Wasteload

 

Allocation (WLA) Procedure,? [effective date], or from instream studies of the mixing
characteristics during low ?ow. in addition, the most restrictive of the following factors will be

met:

 

ITEM 3. Amend subparagraph 61.2(4) as follows:

(4) A discharger to interior streams and rivers, the Big Sioux and Des Moines Rivers,
and the Mississippi or Missouri Rivers may provide to the department, for consideration,
instream data which technically supports the allowance of an increased percentage of the stream

?ow contained in the mixing zone due to rapid and complete mixing. Any allowed increase in

mixing zone ?ow would still be governed by the mixing zone length restrictions. The

submission of data should. follow the guidance provided in the WW

 

?Iowa Wasteload Allocation (WLA) Procedure,? [effective date].

ITEM 4. Amend paragraph 61.2(4) introductory paragraph, as follows:

6. For ammonia criteria noted in Table 3, the dimensions of the mixing zone and the zone

of initial dilution will be calculated using a mathematical model presented in the ?Sappo?ing

 

?Iowa Wasteload Allocation (WLA) Procedure,? effective date], or from
instream studies of the mixing characteristics during low ?ow. In addition, the most restrictive

of the following factors will be met:

ITEM 5. Amend paragraph 61.2(4) as follows:

f. For ammonia criteria noted in Table 3, the stream flow used in determining wasteload

allocations to ensure compliance with the chronic criteria of Table 3 will be that value contained

 

at the boundary of the allowed mixing zone. This stream flow may not exceed the percentages of

the design iow stream ?ow noted in 61.2(4) ?e as measured at the point of discharge.

The pH and temperature values at the boundary of the mixing zone used to select the
chronic ammonia criteria of Table 3 will be from one of the following sources. The source of the
pH and temperature data will follow the sequence listed below, if applicable data exists from the

source.

(1) Specific pH and temperature data provided by the applicant gathered at their

mixing zone boundary. Procedures for obtaining this data are noted in the ESisipqaerting

 

?Iowa Wasteload Allocation (WLA) Procedure,? [effective date].
(2) Regional background pH and temperature data provided by the applicant gathered

along the receiving stream and representative of the background conditions at the outfall.

Procedures for obtaining this data are noted in the 

. ?Iowa Wasteload

 

Allocation (WLA) Procedure,? [effective date].

?1

(3) The statewide average median background values as determined by the

department 

 

The stream flow in the zone of initial dilution used in determining ef?uent limits to ensure
compliance with the acute criteria of Table 3 may not exceed 5 percent of the calculated ?ow
associated with the mixing zone for facilities with a dilution ratio of less than or equal to 2: and
not exceed 10 percent of the calculated ?ow associated with the mixing zone for facilities with a

dilution ratio of greater than. 2:1. The pH and temperature values at the boundary of the zone of

 

initial dilution used to select the acute ammonia criteria of Table 3 will be from one of the
following sources and follow the sequence listed below, if applicable data exists from the
source.

1. Speci?c ef?uent pH and temperature data if the dilution ratio is less than or equal to
2:1.

2. If the dilution ratio is greater than 2:1, the logarithmic average pH of the ef?uent
and the regional or statewide pH provided in will be used. In addition, the ?ow
proportioned average temperature of the ef?uent and the regional or statewide temperature

provided in 6l.2(4) will be used. The procedures for calculating these data are noted in

 

revised?en?NovembeH?lv?lggi) ?lowa Wasteload Allocation (WLA) Procedure,? [effective date].

ITEM 6. Amend subparagraph 61.2(4) as follows:

(4) A discharger to interior streams and rivers, the Big Sioux and Des Moines Rivers,
and the Mississippi and Missouri Rivers may provide to the department, for consideration,
instream data which technically supports the allowance of an increased percentage of the stream

flow contained in the mixing zone due to rapid and complete mixing. Any allowed increase in

mixing zone ?ow would still be governed by the mixing zone length restrictions. The

submission of data should follow the guidance provided in the i8upperting?Deeument?for?lowa

 

2909??Iowa Wasteload Aliocation (WLA) Procedure.? [effective date].

ITEM 7. Amend paragraph 61.3(2) as follows:

 

g. Cations and anions guideline values to protect livestock watering may be found
in the

?Iowa Wasteload Allocation (WLA)

Procedure,? [effective date].

 

 

ITEM 8. Amend paragraph 61.3(2) as follows:

h. The Escherichia coli (E. coli) content of water which enters a sinkhole or losing stream

segment, regardless of the water body?s designated use, shall not exceed a Geometric Mean value

of 126 organisms/ 100 No new

wastewater discharges will be allowed on watercourses which directly or indirectly enter

sinkholes or losing stream segments.

ITEM 9. Amend subparagraph 61.3(3) as follows:
61.3(3) Speci?c water quaZiij/ criteria.

a. Class waters. Waters which are designated as Class ?Al or in subrule
61.3(5) are to be protected for primary contact, secondary contact, and children?s recreational
uses. The general criteria of subrule 613(2) and the following specific criteria apply to all Class
waters.

(1) The Escherichia coli (E. coli) content shall not exceed the levels noted in the Bacteria

Criteria Table when the Class or uses can reasonably be expected to occur.

Bacteria Criteria Table (organisms/l 00 m1 of water)

 

 

Use or Category

Geometric Mean

 

 

 

Class A1
3/15?11/15 126
11/16 3/14 Does not apply Qees?net?aeely

 

Class A2 (Only)

 

 

 

 

 

 

 

 

3/15?ll/15 630

11/16 3/14 Does not apply Dees?not?aeely
[Class A2 and 
or 01W or ONR

Year-Round 630
Class A3

3/15?11/15 126

1/16 3/14 Does not apply Dees?not?apoly

 

 

Class A1 - Primary Contact Recreational Use
Class A2 - Secondary Contact Recreational Use

Class A3 Children?s Recreational Use

 

 

 

When a water body is designated for more than one of the recreational uses, the most

stringent criteria for the appropriate season shall apply.

ITEM 10. Amend subrule 61.3(5) as follows:
61.3(5) Surface water classification. The department hereby incorporates by reference

?Surface Water Classi?cation,? effective June 17, 2015. This document may be obtained on the

 

department?s Web site at -

Standards/Ri?esraspx 

 

ITEM 11. Amend subrule 61.3(6) as follows:
61.3(6) Cold waler use designation assessment protocol. The department hereby
incorporates by reference ?Cold Water Use Designation Assessment Protocol,? effective

December 15, 2004. This document may be obtained on the department?s Web site

at 

 

 

ITEM 12. Amend subrule 61.3(7) as follows:

61.3(7) Warm water stream use assessment and attainability analysis protocol. The
department hereby incorporates by reference ?Warm Water Stream Use Assessment and
Attainability Analysis Protocol,? effective March 22, 2006. This document may be obtained on

the department?s Web site

at 

 

ITEM 13. Adopt the following new subrule 61.3(9) as follows:
61.3(9) Iowa Wasteload Allocation (WLA) Procedure. The department hereby
incorporates by reference ?Iowa Wasteload Allocation (WLA) Procedure,? [effective date]. This

document may be obtained on the department?s Web site at 

ITEM 14. Amend subrule 62.8(2) as follows:

62.8(2) Ef?uent limitations necessary to meet water quality standards. No ef?uent, alone
or in combination with the ef?uent of other sources, shall cause a violation of any applicable
water quality standard. When it is found that a discharge that would comply with applicable
effluent standards in or 567?625(4558) or ef?uent
limitations in would cause a violation of water quality standards, the discharge
will be required to meet the water quality?based ef?uent limits (WQBELS) necessary to achieve
the applicable water quality standards as established in 567?Chapter 61. Any such ef?uent limit

shall be derived from the calculated waste load allocation, as described in ESwapsrang?Beetunes-t

 

 

2999?]owa Wasteload Allocation (WLA) Procedure,? [effective date] or the waste load
allocation as required by a total maximum daily load, whichever is more stringent. The

translation of waste load allocations to WQBELS shall use Iowa permit derivation methods, as

 
   

. n't- 
?Iowa Wasteload Allocation (WLA)
Procedure,? [effective 

 
 

 

 

 

Date

 

Chuck Gipp, Director