Total Maximum Daily Load

{
  "id": "MLC-T-ENV-028285",
  "term": "Total Maximum Daily Load",
  "field": "Environment",
  "definition": "1. Generally refers to plans under the Clean Water Act that limit the amount of pollutant discharge over time.\n\n2. The sum of the individual wasteload allocations (WLAs) for point sources, load allocations (LAs) for nonpoint sources and natural background, plus a margin of safety (MOS). TMDLs can be expressed in terms of mass per time, toxicity, or other appropriate measures that relate to a state's water quality standard.\n\n3. The sum of the individual wasteload allocations (WLAs) for point sources and load allocations (LAs) for nonpoint sources and natural background. Additional information on TMDLs can be found at http://cfpub.epa.gov/npdes/stormwater/tmdl.cfm. To determine if there is an approved or established TMDL on your project's receiving water, refer to http://cfpub.epa.gov/npdes/stormwater/cgp.cfm for state and regional specific TMDL information related to the construction general permit. You may also have to contact your EPA regional office or state agency. http://cfpub.epa.gov/npdes/contacts.cfm?program_id=6&type=STATE\n\n4. Defines the pollutant load that a water body can acquire without violating water quality standards, and allocates the pollutant loading between contributing point sources and non-point sources.\n\n5. The sum of the individual wasteload allocations (WLAs) for point sources, load allocations (LAs) for nonpoint sources and natural background, and a margin of safety (MOS). TMDLs can be expressed in terms of mass per time, toxicity, or other appropriate measures that relate to a state's water quality standard.\n\n6. The sum of the individual wasteload allocations (WLAs) for point sources and load allocations (LAs) for nonpoint sources and natural background. If a receiving water has only one point sources discharger, the TMDL is the sum of that point source WLA plus the LAs for any nonpoint sources of pollution and natural background sources, tributaries, or adjacent segments. TMDLs can be expressed in terms of mass per time, toxicity, or other appropriate measure that relates to a state of water quality standards. If best management practices (BMPs) or other nonpoint source pollution control actions make more stringent load allocations practicable, WLAs can be made less stringent. Thus, the TMDL process provides for nonpoint source control trade-offs. (40 CFR 130.2(I))\n\n7. A calculation of the highest amount of a pollutant that a water body can receive and safely meet water quality standards set by the state, territory, or authorized tribe.\n\n8. The total allowable pollutant load to a receiving waterbody, such that any additional loading will produce a violation of water quality standards.\n\n9. the maximum amount of a pollutant that a waterbody can receive and still meet applicable water quality standards. It is the sum of the allocations for point sources (called wasteloads) and allocations for nonpoint sources (called loads) and natural background with a margin of safety (CWA section 303(d)(1)(c)). The TMDL can be described by the following equation: TMDL = LC = ΣWLA + ΣLA + MOS\n\n10. The amount, or load, of a specific pollutant that a waterbody can assimilate and still meet the water quality standard for its designated use. For impaired waters the TMDL reduces the overall load by allocating the load among current pollutant loads (from point and nonpoint sources), background or natural loads, a margin of safety, and sometimes an allocation for future growth.\n\n11. A regulatory term in the U.S. Clean Water Act, describing a value of the maximum amount of a pollutant that a body of water can receive while still meeting water quality standards. Alternatively, TMDL is an allocation of that water pollutant deemed acceptable to the subject receiving waters. TMDLs have been used extensively by the EPA and state environmental agencies in implementing the Clean Water Act by establishing maximum pollution limits for industrial wastewater dischargers.\n\n12. A calculation of the highest amount of a pollutant that a waterbody can receive and safely meet water quality standards set by the state, territory, or authorized tribe.\n\n13. Sum of the individual WLAs for point sources and LAs for nonpoint sources and natural background. If a receiving water has only one point source discharger, the TMDL is the sum of that point source WLA plus the LAs for any nonpoint sources of pollution and natural background sources, tributaries, or adjacent segments. TMDLs can be expressed in terms of either mass per time, toxicity, or other appropriate measure. If Best Management Practices (BMPs) or other nonpoint source pollution controls make more stringent load allocations practicable, then wasteload allocations can be made less stringent. Thus, the TMDL process provides for nonpoint source control tradeoffs.\n\n14. The sum of the individual wasteload allocations (WLAs) for point sources and load allocations (LAs) for nonpoint sources and natural background. If a receiving water has only one point source discharger, the TMDL is the sum of that point source WLA plus the LAs for any nonpoint sources of pollution and natural background sources, tributaries, or adjacent segments. TMDLs can be expressed in terms of either mass per time, toxicity, or other appropriate measure. If best management practices (BMPs) or other nonpoint source pollution controls make more stringent load allocations practicable, then wasteload allocations can be made less stringent. Thus, the TMDL process provides for nonpoint source control tradeoffs.\n\n15. Sum of the individual wasteload allocations for point sources and load allocations for nonpoint sources and natural background, as more fully defined at 40 CFR 130.2(i). A TMDL sets and allocates the maximum amount of a pollutant that may be introduced into a water body and still assure attainment and maintenance of water quality standards.\n\n16. Calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards and an allocation of that amount to the pollutant's source.\n\n17. Regulatory term in the U.S. Clean Water Act, describing a value of the maximum amount of a pollutant that a body of water can receive while still meeting water quality standards. Alternatively, TMDL is an allocation of that water pollutant deemed acceptable to the subject receiving waters. TMDLs have been used extensively by the EPA and state environmental agencies in implementing the Clean Water Act by establishing maximum pollution limits for industrial wastewater dischargers.\n\n18. Calculation of the maximum amount of a pollutant allowed to enter a waterbody so that the waterbody will meet and continue to meet water quality standards for that particular pollutant. A TMDL determines a pollutant reduction target and allocates load reductions necessary to the source(s) of the pollutant. Sometimes referred to as a “pollution diet” for a waterbody.\n\n19. A calculation of the maximum amount of a pollutant that a waterbody can receive and still safely meet water quality standards.\n\n20. A calculation of the maximum amount of a pollutant a waterbody can receive and still meet applicable water quality standards (accounting for seasonal variations and a margin of safety), including an allocation of pollutant loadings to point sources (waste load allocations) and nonpoint sources (load allocations).\n\n21. The maximum amount of pollution that a water body can receive without violating water quality standards. Total Maximum Daily Loads are the sum of point and nonpoint source loads.",
  "abbreviation": "TMDL",
  "subject": "Water",
  "see_also": [
    "Total Maximum Daily Loads"
  ],
  "references": [
    "Watershed Protection Glossary",
    "Sediment Total Maximum Daily Loads (TMDLs) Glossary",
    "National Pollutant Discharge Elimination System (NPDES) Glossary",
    "Chesapeake Bay Glossary; DWMAPS Glossary",
    "Total Maximum Daily Loads (303d) Glossary; Impaired Waters and Total Maximum Daily Loads Glossary",
    "Urban Watershed Management Research Terminology",
    "Terms of Environment",
    "CADDIS Glossary",
    "Chesapeake Bay TMDL Glossary",
    "Watershed Planning Glossary of Terms; Watershed Planning Glossary",
    "CMAQ Glossary",
    "EPA Guidance for Federal Land Management in the Chesapeake Bay Watershed Glossary at http://www.epa.gov/owow_keep/NPS/chesbay502/pdf/chesbay_glossary.pdf; Federal Land Management in the Chesapeake Bay Watershed Glossary",
    "40 CFR 130.2 (CFR 2013)",
    "NPDES Permit Writers Glossary; NPDES Permit Writers Manual Glossary",
    "40 CFR 132.2 (CFR 2013)",
    "Aquatic Biodiversity Glossary",
    "Community Multiscale Air Quality (CMAQ) Glossary",
    "How's My Waterway Glossary",
    "NSTEPS Online Glossary of Terms",
    "Water Quality Trading Toolkit for Permit Writers Glossary",
    "Nonpoint Pollution Source from Agriculture Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/total-maximum-daily-load/"
}