Bowling Green Water Pollution Control (WPC)

Record · Permits

Bowling Green Water Pollution Control (WPC)

2PD00009.fs

[verified]

Fields

facility_name

Bowling Green Water Pollution Control (WPC)

permit_no

2PD00009*TD

permit_action

renewal

applicant

City of Bowling Green, 304 North Church Street, Bowling Green, OH 43402

application_no

OH0024139

public_notice_no

22-02-025

public_notice_date

2022-02-22

comment_period_end

2022-03-25

facility_address

Bowling Green WPC, 901 North Dunbridge Road, Bowling Green, OH 43402, Wood County

receiving_water

Poe Ditch

subsequent_stream_network

North Branch Portage River to Portage River to Lake Erie

page_count

receiving_water_chain

citation Fact Sheet 2PD00009, Page 6 of 35, "LOCATION OF DISCHARGE/RECEIVING WATER USE CLASSIFICATION"
tag [verified]
outfall_receptor Poe Ditch
outfall_river_mile 2.5
poe_ditch_river_code 16-108
hydrologic_unit_code 04100010-03-01
county Wood
ecoregion Huron-Erie Lake Plain
poe_ditch_use_designations
- Limited Resource Water
- Agricultural Water Supply
- Industrial Water Supply
- Secondary Contact Recreation
confluence "A short distance downstream of Bowling Green WPC, Poe Ditch discharges to the North Branch of the Portage River at River Mile 8.56 (Ohio EPA River Code: 16-007)."
north_branch_portage_river_mile 8.56
north_branch_portage_river_code 16-007
north_branch_portage_use_designations
- Warmwater Habitat
- Agricultural Water Supply
- Industrial Water Supply
- Primary Contact Recreation
criteria_applied_from North Branch Portage River. Quoted: "Water quality criteria associated with these uses are applied to Bowling Green WPC to be protective of this higher quality stream."

facility

citation Fact Sheet 2PD00009, Pages 6-7 of 35, "FACILITY DESCRIPTION"
tag [verified]
constructed 1982
most_recent_upgrade 2021 — "improvements to the aeration system were installed to improve control for biological nutrient removal"
average_design_flow_mgd 10
peak_hydraulic_capacity_mgd 30
service_area City of Bowling Green and the Villages of Portage and Rudolph
population_served ~32000
equalization_basin_mg 4
collection_system 60% separate sewers, 40% combined sewers
infiltration_inflow_mgd 0.5
treatment_processes
- Bar, mechanical screen
- Grit, scum removal
- Primary sedimentation
- Secondary treatment - activated sludge
- Secondary clarification
- Tertiary filtration - cloth media
- Ultraviolet disinfection
bypasses none
sludge_processes
- Aerobic digestion
- Centrifuge dewatering
pretreatment_program
- approved yes
- industrial_users 6
- categorical_users 2
- categorical_flow_mgd 0.021
- significant_non_categorical_users 4
- significant_non_categorical_flow_mgd 0.093
cso
- outfalls 1
- outfall_id 002
- ltcp_approved 2008-03
- ltcp_level_of_control four or fewer untreated CSO events per typical year
- ltcp_status "The City has completed implementation of its LTCP and submitted an LTCP Evaluation Report, which concluded that the City had attained compliance with LTCP level of control"
sso
- station 300
- reported_last_five_years 0

receiving_water_assessment

citation Fact Sheet 2PD00009, Pages 8-9 of 35, "ASSESSMENT OF IMPACT ON RECEIVING WATERS"
tag [verified]
section_303d_listing "The North Branch Portage River watershed assessment unit, which includes Poe Ditch in the vicinity of Bowling Green WPC, is listed as impaired for aquatic life, recreation, and human health (fish tissue) use on Ohio's 303(d) list."
tmdl
- approved 2011-09
- basin Portage River
- underlying_data 2008, reported in the TSD "Biological and Water Quality Survey of the Portage River Basin, Select Maumee River Tributaries, and Select Lake Erie Tributaries, 2006 - 2008"
aquatic_life_impairment "The North Branch Portage River is impaired for aquatic life use due to nutrient enrichment downstream of Bowling Green WPC. The TSD identified Bowling Green WPC as a source, showing significant spikes in nutrient concentrations downstream of the facility (Figure 4)."
aquatic_life_second_cause "The aquatic life use in North Branch Portage River is also impaired due to siltation caused by channelization." — a cause this discharger is not named for.
recreation_impairment "Impairments of the primary contact recreation use due to high E. coli levels were identified in Poe Ditch and on the North Branch Portage River up-and downstream of Poe Ditch. Home sewage treatment systems (HSTS), agriculture, and Bowling Green WPC were identified as sources of the impairment."
recreation_exculpatory Carried at equal weight, per the discipline: "To reduce bacteria loads to the receiving stream, the City has implemented its Long Term Control Plan to reduce untreated CSO discharges and has had only two violations of the E. coli effluent limits at the treatment facility in the last five years." The E. coli impairment is identified both UPSTREAM and downstream of Poe Ditch, which is not a pattern this outfall alone can produce.
human_health_impairment "The human health use in North Branch Portage River is impaired due to high polychlorinated biphenyl (PCB) levels found in the tissue of sport fish." No PCB limit or PCB source attribution to this plant appears anywhere in the fact sheet.
phosphorus_management "The TMDL report assessed multiple scenarios for assigning phosphorus reductions but none resulted in reaching the in-stream target. As a result, the TMDL recommended an implementation strategy to address the identified nutrient impairment with a target effluent concentration of 0.5 mg/L for Bowling Green WPC but no formal wasteload allocation was approved. Based on best technical judgement and using the TMDL as guidance, the monthly average limit for total phosphorus was reduced from 1.0 to 0.7 mg/L in permit 2PD00009*SD." The *TD renewal continues those limits pending an Ohio EPA resurvey that, as of this fact sheet, had not happened.

instream_conditions

citation Fact Sheet 2PD00009, Page 30 of 35, "Table 12. Instream Conditions and Discharger Flow"
tag [verified]
basis USGS Gage
basis_footnote "*Flow data from Low-Flow Characteristics of Stream in Ohio through Water Year 1997 and adjusted for drainage area"
stream_flows_cfs
- 1Q10_annual 0.285
- 7Q10_annual 0.364
- 30Q10_summer 0.626
- 30Q10_winter 1.48
- 90Q10_annual 0.865
- harmonic_mean_annual 3.233
mixing_assumption_pct
- average 25
- maximum 100
discharger_flow
- cfs 15.47
- mgd 10
- basis NPDES Application Form 2A
ambient
- hardness_mg_l 331
- ph_summer 7.8
- ph_winter 7.93
- temperature_c_summer 22.72
- temperature_c_winter 3.77
- nitrate_nitrite_mg_l 4.41
- total_filterable_residue_mg_l 734.5
background_no_data
- note Recorded because an absence of data is not an absence of the pollutant. Table 12 gives a background of ZERO for antimony, dissolved hexavalent chromium, free cyanide, MBAS and molybdenum on the stated basis "No representative data available." For MBAS in particular — the parameter that later drove this plant into Category-I noncompliance — the wasteload allocation was computed against an assumed background of zero that Ohio EPA had no ambient datum to support.
- parameters
  - Antimony
  - Dissolved Hexavalent Chromium
  - Free Cyanide
  - MBAS (foaming agents)
  - Molybdenum

reported_performance

citation Fact Sheet 2PD00009, Pages 21-22 of 35, Tables 1-5
tag [verified]
window_note 2016 columns are September-December only; 2021 columns are January-August only. Neither is a full year and neither should be compared to a full-year column without saying so.
effluent_violations_outfall_001
- 2017 2
- 2018 4
- 2019 7
- 2020 15
- 2016a 0
- 2021b 7
- total 35
- by_parameter
  - CBOD_5_day 9
  - Ammonia 11
  - Total_Suspended_Solids 7
  - Mercury 3
  - E_coli 2
  - Phosphorus 2
  - Fecal_Coliform_in_Sludge 1
- permittee_explanation Carried from p. 7: "Many of these violations are associated with the recent facility improvements (2020-21), during which the aeration treatment systems were operating at half capacity."
annual_flow_mgd
- 2017
  - p50 5.21
  - p95 15.49
  - max 29.35
- 2018
  - p50 5.46
  - p95 13.6
  - max 26.27
- 2019
  - p50 5.71
  - p95 14.88
  - max 27.08
- 2020
  - p50 4.62
  - p95 12.12
  - max 25.33
- 2016a
  - p50 4.25
  - p95 9.05
  - max 20.04
- 2021b
  - p50 4.54
  - p95 11.84
  - max 18.03
- note Median flow runs 4.25-5.71 MGD against a 10 MGD average design — the plant has substantial headroom at the median. The 95th percentiles (up to 15.49 MGD) and maxima (up to 29.35 MGD, against a 30 MGD peak hydraulic capacity) are the wet-weather story, not the dry-weather one.
cso_discharges
- 2017
  - occurrences 6
  - volume_mg 126.43
- 2018
  - occurrences 8
  - volume_mg 52.95
- 2019
  - occurrences 4
  - volume_mg 35.66
- 2020
  - occurrences 3
  - volume_mg 42.58
- 2016a
  - occurrences 2
  - volume_mg 26.98
- 2021b
  - occurrences 4
  - volume_mg 44.94
- note 2017 (6) and 2018 (8) exceed the LTCP level of control of four per typical year. The fact sheet does not treat those years as a level-of-control failure — the standard is four per TYPICAL year, and a typical-year determination is a modelling exercise, not a raw count. Recorded as printed; no violation is asserted from this table.
total_phosphorus_loading
- 2017
  - n 25
  - median_mg_l 0.5
  - median_flow_mgd 5.21
  - median_load_kg_day 9.85
- 2018
  - n 24
  - median_mg_l 0.4
  - median_flow_mgd 5.46
  - median_load_kg_day 8.26
- 2019
  - n 27
  - median_mg_l 0.2
  - median_flow_mgd 5.71
  - median_load_kg_day 4.32
- 2020
  - n 43
  - median_mg_l 0.3
  - median_flow_mgd 4.62
  - median_load_kg_day 5.24
- 2016a
  - n 8
  - median_mg_l 0.65
  - median_flow_mgd 4.25
  - median_load_kg_day 10.45
- 2021b
  - n 24
  - median_mg_l 0.4
  - median_flow_mgd 4.54
  - median_load_kg_day 6.87

parameter_assessment

citation Fact Sheet 2PD00009, Page 32 of 35, "Table 14. Parameter Assessment"
tag [verified]
group_5_limits_recommended
- ammonia_summer_avg_mg_l 1.7
- ammonia_winter_avg_mg_l 4.2
- b2ehp_avg_ug_l 8.4
- b2ehp_max_ug_l 1120
- mbas_max_mg_l 0.51
- mercury_avg_ng_l 1.3
- mercury_max_ng_l 1700
mercury_note "Mercury becomes a Group 5 parameter based upon the loading test [OAC 3745-2-06(B)]" — i.e. by load, not by concentration.
group_2_no_limit
- Antimony
- Arsenic
- Cadmium
- Chromium
- Dissolved Hexavalent Chromium
- Copper
- Molybdenum
- Nickel
- Nitrate + Nitrite
group_3_no_limit
- Free Cyanide
- Lead
- Selenium
- Zinc
group_4_monitoring
- Total Filterable Residue

final_effluent_limits_outfall_001

citation Fact Sheet 2PD00009, Page 33 of 35, "Table 15. Final Effluent Limits for Outfall 001"
tag [verified]
loading_basis "Effluent loadings based on average design discharge flow of 10 MGD." Every kg/day figure below is therefore a DESIGN-FLOW loading, not an actual-flow loading; the plant's median flow is roughly half its design flow.
limits
- - parameter Dissolved Oxygen
  - units mg/L
  - daily_minimum 5
  - basis PD
- - parameter Total Suspended Solids
  - units mg/L
  - seven_day_avg 18
  - thirty_day_avg 12
  - load_daily_kg 682
  - load_30day_kg 455
  - basis PD
- - parameter Oil & Grease
  - units mg/L
  - daily_maximum 10
  - basis WQS
- - parameter Ammonia (summer)
  - units mg/L
  - seven_day_avg 2.5
  - thirty_day_avg 1.7
  - load_daily_kg 94.7
  - load_30day_kg 64.4
  - basis WLA
- - parameter Ammonia (winter)
  - units mg/L
  - seven_day_avg 6.3
  - thirty_day_avg 4.2
  - load_daily_kg 239
  - load_30day_kg 159
  - basis WLA
- - parameter Phosphorus
  - units mg/L
  - seven_day_avg 1.1
  - thirty_day_avg 0.7
  - load_daily_kg 41.7
  - load_30day_kg 26.5
  - basis PTS/BPJ
- - parameter E. coli
  - units #/100 mL
  - seven_day_avg 284
  - thirty_day_avg 126
  - basis WQS
- - parameter Methyl Blue Active Substances (MBAS)
  - units mg/L
  - daily_maximum 0.51
  - load_daily_kg 19.4
  - basis WLA
- - parameter Bis(2-ethylhexyl) phthalate
  - units ug/L
  - daily_maximum 1120
  - thirty_day_avg 8.4
  - load_daily_kg 42.4
  - load_30day_kg 0.318
  - basis WLA
- - parameter Mercury
  - units ng/L
  - daily_maximum 1700
  - thirty_day_avg 1.3
  - load_daily_kg 0.0644
  - load_30day_kg 0.00005
  - basis WLA
- - parameter CBOD5
  - units mg/L
  - seven_day_avg 12
  - thirty_day_avg 10
  - load_daily_kg 455
  - load_30day_kg 379
  - basis PD
- - parameter pH
  - units SU
  - daily_maximum 9
  - daily_minimum 6.5
  - basis WQS
monitor_only
- Water Temperature
- Precipitation
- Total Kjeldahl Nitrogen
- Nitrate plus Nitrite
- Orthophosphate
- Nickel
- Zinc
- Cadmium
- Lead
- Chromium
- Copper
- Dissolved Hexavalent Chromium
- Flow Rate
- Free Cyanide
- Total Filterable Residue
- Acute/Chronic Toxicity (C. dubia, P. promelas)
basis_legend
- BPJ Best professional judgment
- BTJ Best Technical Judgment
- M DSW NPDES Permit Guidance 1 (monitoring frequency, sanitary discharges)
- PD Plant Design (OAC 3745-33-05(E))
- PMR Phosphorus monitoring requirements (ORC 6111.03)
- PTS Phosphorus Treatment Standards (OAC 3745-33-06(C))
- WET Minimum WET testing requirements (OAC 3745-33-07(B)(11))
- WLA Wasteload Allocation procedures (OAC 3745-2)
- WQS Ohio Water Quality Standards (OAC 3745-1)

summary_of_permit_conditions

citation Fact Sheet 2PD00009, Page 2 of 35, "SUMMARY OF PERMIT CONDITIONS"
tag [verified]
quoted_changes
- "New limits for bis(2-ethylhexyl) phthalate (B2EHP) and methyl blue activated substances (MBAS) are proposed due to reasonable potential to exceed the wasteload allocation. A 36-month compliance schedule is proposed for the permittee to attain compliance with the new limits."
- "Lower final effluent limits are proposed for ammonia (summer and winter), due to plant design limits not being protective of water quality standards. A 36-month compliance schedule is proposed..."
- "Monitoring for E. coli at upstream station 801 and downstream station 901 is proposed to change from summer to June-August and from monthly to once per two weeks."
- "New monitoring for total phosphorus as station 901 is proposed to provide data for future water quality studies."
- "Monitoring for CBOD5 and TSS at CSO station 002 is proposed to be removed."
- "A new condition is proposed in Part II of the permit that requires continued compliance with the Long Term Control Plan level of control for combined sewer overflows."
antidegradation "No antidegradation review was necessary." (p. 1)

⚠ Gaps in the record

Table 12's low flows are NOT measured on Poe Ditch, and not measured anywhere near Bowling Green. They are drainage-area-adjusted from USGS gauge 04195500 (Portage River at Woodville) over 1951-97 — a record that closed before the network's own derived 7Q10 window (1980-2024) opens. The footnote is explicit: "Flow data from Low-Flow Characteristics of Stream in Ohio through Water Year 1997 and adjusted for drainage area." Treat the 0.364 cfs as the REGULATORY denominator that this permit's limits were actually computed against, not as a measurement of the ditch, and do not reconcile it against a derived value by preferring one — they are different arithmetic over different records. Same posture as Ottawa (data/extracted/oepa/ottawa/2PD00028.fs.npdes.yaml).
The plant is far larger than the water it discharges into. Table 12 states the discharger flow as 15.47 cfs (10 MGD) against an annual 7Q10 of 0.364 cfs in the same table — a ratio of about 42 to 1. Under design-flow low-flow conditions Poe Ditch below this outfall is effluent, not diluted effluent. This is a [verified] reading of two numbers printed in one table; the ratio itself is arithmetic and is tagged [inference] where it is asserted downstream.
The water quality criteria applied to this discharge are NOT Poe Ditch's own. Poe Ditch is designated Limited Resource Water; the fact sheet states on p. 6 that the criteria associated with the North Branch Portage River's higher uses (Warmwater Habitat, Primary Contact Recreation) "are applied to Bowling Green WPC to be protective of this higher quality stream." A screen that reads Poe Ditch's LRW designation and stops there will apply the wrong criteria.
The total phosphorus limit was NOT tightened by this permit. The reduction from 1.0 to 0.7 mg/L happened in the PRIOR action, permit 2PD00009*SD (p. 9: "the monthly average limit for total phosphorus was reduced from 1.0 to 0.7 mg/L in permit 2PD00009*SD"). This *TD renewal CONTINUES it — "this permit proposes that the same phosphorus limits be continued under the adaptive management approach." Any claim that the 2022 renewal cut the phosphorus limit is wrong; the 2022 renewal declined to cut it further while Ohio EPA waited to resurvey.
The TMDL's own target for this plant is 0.5 mg/L total phosphorus and it was never adopted as a limit. Page 9: the TMDL "assessed multiple scenarios for assigning phosphorus reductions but none resulted in reaching the in-stream target," and it "recommended an implementation strategy ... with a target effluent concentration of 0.5 mg/L for Bowling Green WPC but no formal wasteload allocation was approved." The operative 0.7 mg/L limit rests on best technical judgement, not on an approved WLA.

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