Airport Sewer IA DNR Inspection
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STATE OF IOWA
THOMAS j, VILSACK, GOVERNOR
SALLyj, PEDERSON, LT, GOVERNOR
DEPARTMENT OF NATURAL RESOURCES
jEFFREY R. YaNK, DIRECTOR
CERTIFIED MAIL
May 21, 2004
City of Dubuque
City Hall
13 & Central
Dubuque, IA 52001
ATTN: Honorable Mayor & City Council
RE:
Dubuque Regional Airport Wastewater Treatment Facility Inspection
NPDES Permit #: 3126002
Dear Honorable Mayor & City Council:
Enclosed is the report of the recent inspection of the above facility conducted by Sue Miller of
the Field Office #1 staff.
We believe you will find the report self-explanatory. All requirements listed in this report must be
completed as identified in this report.
If you have any questions about the inspection or report, please contact Sue Miller or myself at
this office.
m1J~
Mike Wade
Environmental Specialist
cc:
Charles Furrey, IDNR Wastewater Section, (w/encl.)
Paul Horsfall, Dubuque Water Pollution Control Facility, 795 Julien Dubuque Dr.,
Dubuque, IA 52003 (w/encl.)
File: Dubuque Regional Airport WW
FIELD OFFICE #1 / 909 West Main Suite 4/ Manchester, iA 52057
563-927-2640 / FAX 563-927-2075 / www.iowadnr.com
FACILITY NAME: PLANT GRADE:
Dubuque Regional Airport Wastewater Treatment WW1L
Laaoon
ADDRESS: I CITY: STATE: I ZIP: I PHONE:
RR#3 Dubuque Iowa 52001 563-589-4176
RESPONSIBLE AUTHORITY/OWNER:
City of Dubuque
RESPONSIBLE NAME: I GRADE: I CERTIFICATION NUMBER:
OPERATOR Paul Horsfall IV 3112
DESIGN AVERAGE MGD: MAXIMUM MGD: POUNDS BODIDAY: PE (BOD):
CAPACITY 0.006 0.006 5 30
NOW AVERAGE MGD: MAXIMUM MGD: POUNDS CBOD/DAY: PE (BOD):
TREATING 0.00535(2003) 0.012 (May 2001) NA NA
PERIOD REVIEWED: POPULATION SERVED:
01/01/01 - 03/31/04 Transient pop,
RECEIVING Unnamed Tributary to Granger Creek B(LR)
STREAM
Three cell, completely mixed aerated lagoon
I
DATE LAST INSPECTION:
04/23/1990
Routine Compliance Inspection
TITLE:
Wastewater Operator
Assistant Operator
Air ort Maintenance
SELF-
MONITORING
EFFLUENT
LIMITATIONS
SAMPLES THIS
INSPECTION
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Required Data on Reports:
D Sat. ¡g¡ Marg.* D Unsat.*
Testing Adequacy:
D Sat. ¡g¡ Marg.* D Unsat.*
LAB DATA ATTACHED?
DYes D No
COMPLIANCE
SCHEDULE
INSPECTOR:
NAME: Sue Miller, Environmental Specialist
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. NAME: Mike W ¡de, Environmental Specialist
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REVIEWER:
NPDES PERMIT COMPLIANCE:
The monthly operation reports (MORs) were reviewed for the reporting period from January 1,2001 through
March 31, 2004.
Self- Monitoring - The operation reports were submitted regularly and on time; and it appears that the
wastewater testing parameters of the NPDES permit are being consistently entered at the required
frequencies on the monthly reports.
Design Capacity/Effluent Limitations - During the above mentioned reporting period the following
observations were made:
The design influent flow rates are 0.006 MGD AWW and 0,006 MGD MWW. The AWW was exceeded
during March 2001, April 2003 and March 2004 and the MWW was exceeded eleven (11) months during
2001, nine (9) months during 2002, twelve (12) months during 2003 and three (3) months thus far in 2004.
The 30-day and 7-day average CBODs effluent limitations are 25 mg/L and 40 mg/L respectively. During
the above mentioned reporting period the facility appeared to be in compliance with the effluent
concentration limitations of the current NPDES permit, although the average mass limit was exceeded in
May 2003.
. The 30-day and 7-day average total suspended solids (TSS) effluent limitations are 80 mg/L and 120 mg/L
respectively. During the above mentioned reporting period the facility appeared to be in compliance with
the effluent limitations of the current NPDES permit.
FACILITY EVALUATION:
Collection System -
This system appears to be hydraulically overloaded. Infiltration/inflow (1/1) may be a contributing to the
problem. Large amounts of clear water could be part of the cause of hydraulic overload reducing the efficiency
of treatment units. These sources include, but are not limited to roof drains, basement sumps, storm sewer
interconnections and leaking manholes. The owner must initiate a program to identify and eliminate sources
of 1/1.
The operator stated that there have been no bypasses of the treatment system to the best of his knowledge.
For future reference, see the attached guidelines for bypass event reporting.
Lift Station(s) -The Dubuque Regional Airport is served by one lift station located across the road from the
main terminal. The lift station appeared to be well maintained and clean.
Aeration System - The aeration system consists of two submerged diffusers in each of cells 1 and 2. Cell 3
is a quiescent cell. There appears to be adequate dissolved oxygen in the secondary cell at all times. DO
periodically drops below 3.0 mg/I in the primary cell and occasionally below 2.0 in the final cell. This may be a
factor of the time of day that the sample was collected, but could also be an indication of organic overload.
Within 30 days of the receipt of this report, the owner must collect and analyze 24-hour composite influent
BODs, CBODs, TSS and pH samples to determine if the existing loads on the system are within the design and
to calculate whether 85% removal is being achieved as per the facility permit. If influent sample analysis
shows that influent loads average more than 5 Ibs. BODs/day, within 90 days a plan of action must be
submitted that addresses what steps the owner will take to upgrade the facility to adequately treat the organic
loads it is receiving now and realistically plans to receive in the future.
Lagoon Structures -
The operator said that cell 3 has a problem with excess algae and duckweed growth. To control the excess
growth, the maintenance crew adds an algaecide on a regular basis. At the time of this inspection, the water
in cell 3 was a deep blue color, as was the effluent.
Aerated lagoons that have an abundance of blue-green algae present are either organically overloaded or
have some deficiency in the aeration system. The use of algaecide must be discontinued due to possible
toxicity to aquatic life, unless effluent monitoring and limits are established by the NPDES permit.
An acceptable alternative to the use of algaecide is the mechanical or manual removal of floating algae mats.
A layer of duckweed will also inhibit algae growth by shading the sunlight. Manual removal of the duckweed
prior to cold weather will keep the dying duckweed from adding to the BODs of the cell.
The effluent from cell 3 flows to a rock lined ditch and appears to soak into the ground. The operator reported
"No Discharge" or "Little or No Effluent Flow" on every monthly operating report submitted for the reporting
period January 2001 through March 2004. The effluent samples that are reported on the monthly operation
reports have been taken from cell 3 or cell 2, if cell 3 is frozen, rather than from the outfall. The operator must
collect effluent samples from the outfall if there is any discharge at all. Samples from lagoon cells are not
acceptable.
Influent flow consistently exceeds effluent flow in the Dubuque Regional Airport lagoon system. This suggests
that the lagoons may be leaking. Mr. Horsfall said that a leaking lagoon study was performed a number of
years ago that determined the lagoons were not leaking. Mr. Horsfall said he was unable to find the report. If
the previously prepared leaking lagoon report can be located, the city must submit it to this office within 10
days of the receipt of this report for evaluation. If the previous report cannot be found or is determined by the
department to be inadequate, the owner must have an engineering evaluation performed to determine if the
lagoons are leaking. If the lagoon system is determined to be leaking, within 90 days a plan of action must be
submitted that addresses what steps the owner will take seal the lagoon system.
All valves and control equipment should be repaired and maintained in proper working order at all times and
regularly exercised to keep the valves in good working order.
Flow Measurement-
Time clocks on the lift station pumps are used for calculating influent flow. This method of flow needs to be
recalibrated at least every twelve months to take into account for impeller wear. These calibrations must be
kept with other maintenance records. As stated in the Collection System Section of this report, the influent
flow readings for this system indicate that the system is hydraulically overloaded. An 1/1 study must be
initiated, but the accuracy of the flow data must also be verified. Within 30 days of the receipt of this report,
the operator must calibrate the lift station pumps to ensure that accurate flow data is provided to the
department.
The facility permit also requires instantaneous effluent flows. The outfall is not equipped with a flow
measurement device.
General Staffing -
The operator of this facility is Paul Horsfall, who is also the operator of the City of Dubuque Water Pollution
Control Facility. Bill Jungk and Don Haverland assist Mr. Horsfall will daily operations.
Miscellaneous -
Sludge- The operator should investigate the thickness of the sludge layer in the lagoon cells. Too much
sludge can limit the amount of available storage. If the operator determines that sludge must be removed
from the lagoon, any sludge removed must be handled in accordance with 567 lAC Chapter 67.
SUMMARY OF REQUIREMENTS
1. The owner must initiate a program to identify and eliminate sources of 1/1.
2. Within 30 days of the receipt of this report, the owner must collect and analyze 24-hour composite influent
BODs, CBODs, TSS and pH samples to determine if the existing loads on the system are within the design
and to calculate whether 85% removal is being achieved as per the facility permit. If influent sample
analysis shows that influent loads average more than 5 Ibs. BODs/day, a plan of action must be submitted
within 90 days that addresses what steps the owner will take to upgrade the facility to adequately treat the
organic loads it is receiving now and realistically plans to receive in the future.
3. The use of algaecide must be discontinued due to possible toxicity to aquatic life, unless effluent
monitoring and limits are established by the NPDES permit.
4. The operator must collect effluent samples from the outfall if there is any discharge at all. Samples from
lagoon cells are not acceptable.
5. If the previously prepared leaking lagoon report can be located, the city must submit it to this office within
10 days of the receipt of this report for evaluation. If the previous report cannot be found or is determined
by the department to be inadequate, the owner must have an engineering evaluation performed within 90
days to determine if the lagoons are leaking. If the lagoon system is determined to be leaking, a plan of
action must be submitted that addresses what steps the owner will take seal the lagoon system.
6. All valves and control equipment should be repaired and maintained in proper working order at all times
and regularly exercised to keep the valves in good working order.
7. Within 30 davs of the receipt of this report, the operator must calibrate the lift station pumps to ensure that
accurate flow data is provided to the department.
8. If the operator determines that sludge must be removed from the lagoon, any sludge removed must be
handled in accordance with 567 lAC Chapter 67.
SUMMARY OF RECOMMENDATIONS
1. An acceptable alternative to the use of algaecide is the mechanical or manual removal of floating algae
mats. A layer of duckweed will also inhibit algae growth by shading the sunlight. Manual removal of the
duckweed prior to cold weather will keep the dying duckweed from adding to the BODs of the cell.
2. The operator should investigate the thickness of the sludge layer in the lagoon cells. Too much sludge
can limit the amount of available storage.
Guidelines for Bypass Event Reporting
Iowa DNR Environmental Services
Field Office 1 - Manchester, Iowa
Listed below are the rules in the Iowa Administrative Code that apply to bypass
reporting:
567-63.6(4558) Report of bypass.
63.6(1) Except for bypasses that occur as a result of mechanical failure or acts beyond
the control of the owner, owners of waste disposal systems shall obtain written
permission from the department prior to any bypassing of any sewage or wastes from
the waste disposal system.
63.6(2) In the event that bypassing of sewage or waste occurs as a result of mechanical
failure or acts beyond the control of the owner (other than rain or other precipitation),
said owner shall notify the department by telephone of the bypassing within 12 hours of
the time of the discovery of the bypassing. The owner shall comply with the instructions
of the department calculated to minimize the effect of the bypassing on the receiving
water of the state.
63.6(3) Bypasses other than those described in this rule shall be reported in the records
of operation.
Public Notification for Bypass Events
Notification to the affected public shall be made for any bypass, except for
precipitation related events.
The Field Office shall make the necessary notifications if a drinking water supply
(Class C), primary contact recreation (Class A), high quality water (Class HQ),
public use areas, or other sensitive areas are downstream of the bypass. The
bypasser is required to make other notifications within 4 hours after being notified
by the Department. If the bypasser refuses to make necessary notifications, this
department will make the appropriate notifications. Notification information
should include the following:
. When the bypass occurred or was discovered
. Location of the bypass
.Cause of the bypass
. Estimation of quantity bypassed
. Duration or expected duration of the bypass event
.Water body affected
.Anticipated impact of the bypass (water quality and/or human exposure
risks)
At a minimum, the groups listed below must be contacted:
1. Media
. Daily Newspaper if available
. Area Radio and/or Television Station
2. Local Board of Health
3. Area DNR Conservation Officer
4. Local County Naturalist or Conservation Board
5. Downstream Livestock Water Users
It is strongly recommended that precipitation related bypass events also be
reported to this department within the same 12 hour period, especially when
there is a high human exposure risk from the bypass. For precipitation bypass
events, this department will make all notifications that are deemed necessary by
the department.
A copy of the information provided to the news media must be attached to
monthly operation reports (MORs) that are submitted to this field office. In
addition, the times when the notifications to the affected public where made
should also be included on the MORs.
Monitorina
Water samples of the actual wastewater that was bypassed or if this is not
feasible, raw waste entering the plant must be collected and analyzed for
ammonia, CBOD5, and fecal bacteria.
Disinfection
The Department may require temporary disinfection by chlorination depending on
volume/duration of bypassing, stream classification and use and time of year in
which the public may be using the stream (i.e. class A waters used for canoeing,
tubing, fishing).
Cleanup
The Department may require the cleanup of debris and waste materials
deposited in the area impacted by the bypass. In conjunction with the cleanup,
the department may require lime application to the ground surface or disinfection
of the area with a chlorine solution (recommend a minimum chlorine
concentration of 100 mg/I).
Phone Contacts
The bypass should be reported to a department staff person, a voice mail
message is not acceptable. You can contact the Manchester Field Office by
telephone at (563) 927-2640. After normal office hours contact the 24-hour
emergency response number (515) 281-8694. Field Office staff will assist in
providing additional phone numbers, including Conservation Officers and County
Conservation Boards, upon request.
. Every reasonable effort must be made to prevent any raw waste from
discharging to a water of the state, for any type of bypass.
1. The influent structure at theDubuque Regional Airport wastewater lagoons.
2, Cell 1, the primary cell.
3, Cell2
4, Overflow pipe from Cell 3, the quiescent cell, leads to the outfall.
5. Outfall pipe discharges onto the ground.