| Req ID | Category | Intent | Legal Status | Name | Subdomain(s) | Context | Conditions | Confidence |
|---|---|---|---|---|---|---|---|---|
| #Q001 | administrative | operational | recommended | Site-specific study for continuously renewed MTBE | drinking water, aquatic life, agricultural water, recreational water | Care must be exercised when the water quality guidelines are applied to assess environmental impacts of MTBE, since there may be situations where MTBE concentrations are continuously renewed (e.g., discharge from an industrial operation). In these types of situations, a site-specific study should be undertaken and appropriate site-specific water quality objectives developed based on species present and actual MTBE persistence and concentrations. | Situations where MTBE concentrations are continuously renewed (e.g., discharge from an industrial operation). | high |
| #Q002 | administrative | operational | mandatory | Site-specific impact studies for less stringent objectives | drinking water, aquatic life, agricultural water, recreational water | In some cases, socioeconomic or other factors may justify objectives which are less stringent than the guidelines. Site-specific impact studies would be required in such cases. | When socioeconomic or other factors justify setting water quality objectives that are less stringent than the guidelines. | high |
| Req ID | Category | Intent | Legal Status | Name | Subdomain(s) | Limit Type | Limit Value | Context | Conditions | Confidence |
|---|---|---|---|---|---|---|---|---|---|---|
| #P001 | chemical | aesthetic | guideline | MTBE | drinking water | MAC | <= 0.02 mg / L | Raw Drinking Water (aesthetics) | high | |
| #P002 | chemical | aesthetic | guideline | MTBE | recreational water | MAC | <= 0.02 mg / L | Recreation and Aesthetics | high | |
| #P003 | chemical | health | guideline | MTBE | agricultural water | MAC | <= 11.0 mg / L | Livestock Watering | Concentrations above the taste and odour thresholds that are below the livestock guideline may result in certain livestock avoiding water. | high |
| #P004 | chemical | health | guideline | MTBE | aquatic life | MAC | <= 3.4 mg / L | Aquatic Life (freshwater) | high | |
| #P005 | chemical | health | guideline | MTBE | aquatic life | MAC | <= 0.44 mg / L | Aquatic Life (marine, estuarine) | high | |
| #P006 | chemical | aesthetic | guideline | MTBE | drinking water | AO | <= 0.02 mg/L | Raw Drinking Water Supply | Based on taste and odour thresholds; no adverse health effects expected at this concentration. | high |
| #P007 | chemical | aesthetic | guideline | MTBE | recreational water | AO | <= 0.02 mg/L | Recreation | Aesthetic thresholds for drinking water are applied to waters used for primary-contact recreation. | high |
| #P008 | chemical | health | guideline | MTBE | aquatic life | MAC | <= 3.4 mg/L | Fresh Water Aquatic Life | Interim guideline based on a 100-fold safety factor applied to the lowest LC50 of 340 mg/L (Ceriodaphnia dubia). | high |
| #P009 | chemical | health | guideline | MTBE | aquatic life | MAC | <= 0.44 mg/L | Marine and Estuarine Aquatic Life | Preliminary guideline based on a 100-fold safety factor applied to the lowest LC50 of 44 mg/L (Mysidopsis bahi). | high |
| #P010 | chemical | health | guideline | MTBE | agricultural water | MAC | <= 11.0 mg/L | Livestock Watering | Preliminary guideline based on dairy cattle; concentrations above aesthetic thresholds may cause reduced water intake. | high |
| Req ID | Category | Name | Context | Confidence |
|---|---|---|---|---|
| #D001 | MTBE | Methyl Tertiary-Butyl Ether | high | |
| #D002 | guideline | A maximum and / or a minimum value for a physical, chemical or biological characteristic of water, sediment or biota, which should not be exceeded to prevent specified detrimental effects from occurring to a water use, including aquatic life, under specified environmental conditions. | high | |
| #D003 | objectives | the guidelines modified or adopted to protect the most sensitive designated water use in a particular body of water | high | |
| #D004 | CCME | Canadian Council for Ministers of the Environment | high | |
| #D005 | US EPA | United States Environmental Protection Agency | high | |
| #D006 | persistent variable | a variable that has an extended biodegradation half-life | high | |
| #D007 | ambient water quality guidelines | safe conditions or levels that have province-wide application and are set to protect various water uses | high | |
| #D008 | ambient water quality objectives | the guidelines modified or adopted to protect the most sensitive designated water use in a particular body of water | high |