# Ohio Admin. Code 3745-2-10: Rule 3745-2-10. Wasteload allocation for ammonia-nitrogen toxicity > Ohio · Regulations · In force URL: https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_10 ## Section - **Citation:** Ohio Admin. Code 3745-2-10 - **Heading:** Rule 3745-2-10. Wasteload allocation for ammonia-nitrogen toxicity - **Jurisdiction:** Ohio - **Kind:** Regulations - **Status:** In force - **Text as of:** August 14, 2026 - **Source:** Compiled text - **Location:** Ohio Administrative Code / Agency 3745 / Chapter 3745-2 / Rule 3745-2-10 ## Text 119.03 (A) For discharges of ammonia-nitrogen (NH 3 -N) to flowing receiving waters, the wasteload allocation (WLA) shall be calculated using the following mass balance equation: WLA = [WQC (Q eff + Q up ) - Q up (WQ up )] / Q eff Where: WLA = wasteload allocation, as defined in rule 3745-2-02 of the Administrative Code. WQC = water quality criterion as established in rule 3745-2-04 of the Administrative Code. Q e f f = effluent design flow as established in rule 3745-2-05 of the Administrative Code. Q u p = per cent of the upstream design flow as established in paragraph (B) of this rule. WQ up = background water quality as established in rule 3745-2-05 of the Administrative Code. Alternative modeling methods including, but not limited to, continuous simulation or probabilistic analyses, may be used if the director determines that they are appropriate and protective of water quality criteria. (B) The following stream design flows shall be used to determine WLAs to maintain water quality criteria for NH 3 -N toxicity. (1) May to November: 30Q10 for summer chronic aquatic life. (2) December to February: 30Q10 for winter chronic aquatic life. (3) May to November: 7Q10 for summer acute aquatic life. (4) December to February: 7Q10 for winter acute aquatic life. (C) The WLAs shall use the per cent of stream design flow contained in paragraphs (A)(2)(a) to (A)(2)(c) of rule 3745-2-05 of the Administrative Code. The director may determine design flows for streams that are impacted by reservoirs or other physical alternations by taking into account relevant site-specific factors. Stream design flows for such impacted stream segments shall be established at levels that ensure protection of designated uses. Alternative flows or seasons may be used if the director determines that the flow or season is as protective as those listed in paragraph (B) of this rule that are impacted by reservoirs or other physical alternations by taking into account relevant site-specific factors. Stream design flows for such impacted stream segments shall be established at levels that ensure protection of designated uses. Alternative flows or seasons may be used if the director determines that the flow or season is as protective as those listed in paragraph (B) of this rule. (D) WLAs to maintain the acute criteria shall be required for streams designated as limited resource water in Chapter 3745-1 of the Administrative Code, or for other streams for which the limited resource water criteria are applicable. (E) Exception for direct discharges to lake Erie. If it is necessary to determine a WLA for a direct discharge to lake Erie, the mixing assumptions contained in rule 3745-2-05 of the Administrative Code shall be used. (F) Exception for direct discharges to the Ohio river. If it is necessary to determine a WLA for a direct discharge to the Ohio river, the mixing assumptions contained in rule 3745-2-05 of the Administrative Code shall be used. (G) Multiple discharges. When the director determines that it is necessary to consider multiple discharges in a WLA, the loading capacity may be distributed among discharges using a method deemed appropriate by the director based on site-specific considerations. This WLA shall be developed pursuant to rule 3745-2-05 of the Administrative Code. Supplemental Information Authorized By: 6111.12 , 6111.03 Amplifies: 6111.12 2/9/2025 10/31/1997 ## Nearby sections - [Ohio Admin. Code 3745-2-01 Rule 3745-2-01. Purpose and applicability](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_01.md) - [Ohio Admin. Code 3745-2-02 Rule 3745-2-02. Definitions](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_02.md) - [Ohio Admin. Code 3745-2-03 Rule 3745-2-03. Application of biological survey data to development of water quality-based effluent limitations](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_03.md) - [Ohio Admin. Code 3745-2-04 Rule 3745-2-04. Determinations preliminary to development of water quality-based effluent limitations](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_04.md) - [Ohio Admin. Code 3745-2-05 Rule 3745-2-05. Calculating wasteload allocations](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_05.md) - [Ohio Admin. Code 3745-2-06 Rule 3745-2-06. Application of preliminary effluent limitations](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_06.md) - [Ohio Admin. Code 3745-2-07 Rule 3745-2-07. Additive effects of pollutants](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_07.md) - [Ohio Admin. Code 3745-2-09 Rule 3745-2-09. Whole effluent toxicity provisions and water quality based effluent limit calculation procedures](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_09.md) - [Ohio Admin. Code 3745-2-10 Rule 3745-2-10. Wasteload allocation for ammonia-nitrogen toxicity](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_10.md) - [Ohio Admin. Code 3745-2-11 Rule 3745-2-11. Dissolved oxygen modeling](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_11.md) - [Ohio Admin. Code 3745-2-12 Rule 3745-2-12. Total maximum daily loads](https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_12.md) --- Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/STATE_OH_ADC_3745_2_10. Check the current official text before relying on it. Not legal advice.