Water Quality ENVE 649

Water Quality Hazardous waste winds up in water If it can be legally discharged to water it may not be hazardous

Classes of receiving waters Fresh surface waters Ground water Salt water

Main Laws Fresh surface waters Ground water Salt water Clean Water Act (1972) Clean Water Act Amendments (1987) Ground water Safe Drinking Water Act (1974) Salt water Several

Clean Water Act History “…restore and maintain the chemical physical and biological integrity of the nations’ waters.” “Discharge (from a point source) of pollutants into the navigable waters be eliminated and that, where attainable, the water quality …support fishing and swimming.”

What is a “pollutant” Very broad statutory definition No regulatory or de minimis exception Every discharge is covered, provided other requirements are present.

All point sources will be required to obtain a National Pollution Discharge Elimination System (NPDES) permit.

What is a “point source”? Pipes, for sure Also surface water, if it is channeled or collected Non-point, which are excluded from NPDES are such as: runoff from streets and farms, timber operations, construction sites. (Less restrictive regulatory schemes for these.)

What are “navigable waters” Pretty much all surface waters that might be used in interstate commerce, or might affect interstate commerce, such as lake and wetlands Typically near shore salt waters are included, oceans are not.

The next slides discuss the level of treatment that the NPDES will require. As you go look at the slides, you will realize that the levels of treatment are not “cast in concrete,” but will vary with time and the particular industries and processes involved.

Restrictions on Pollutants Often expressed as weight of pollutant per weight of product Different for different industries Standards applied through individual plants through NPDES permit. Terminology

Industrial Dischargers Existing (old) Direct BPT, Best practical technology, considers cost BAT, Best available technology that is economically achievable. For toxic pollutants BCT, Best conventional technology for “conventional pollutants”-BOD, SS, pH start with BPT and consider improvements BAT is for toxic pollutants

Industrial Dischargers Industrial, new, Direct BADT, Best available demonstrated technology little consideration of cost no variances based on specific circumstances.

So the standards are more stringent for new potential polluters than for existing polluters.

Indirect Dischargers Indirect = through POTW Pretreaters Publicly owned treatment works Pretreaters No NPDES permit, but “pretreatment standards” Must not “pass through” or interfere With POTW operations. Pretreater (the industry that is discharging) is regulated (in the first instance) by POTW, rather than agency.

The POTW themselves must get an NPDES permit.

POTW The permits will require: Achieve “secondary treatment” Numerical values for BOD, SS, pH

NPDES Program National Pollution Discharge Elimination System When writing the permit, the agency will consider two main criteria: 1. Technology based standards on all industries (BADT) 2. Further controls such that receiving waters maintains compliance with water quality standards

Standards for receiving waters Anti-degradation Policy existing uses shall be maintained If existing will support propagation of fish, shellfish, wildlife and recreation, it must be maintained at that level, unless State proves some economic necessity Narrative Criteria Numerical Standards Relate to “use”

Various “Uses” Set by States, EPA reviews Public water supply Protection of fish, shellfish, and wildlife Recreation Agriculture Industry Navigation

Narrative Standards Waters shall be free from discharges that: Settle to form objectionable deposits Float as debris, scum, oil, nuisances Produce objectionable color, taste, odor, turbidity Cause injury or adverse physiological responses in humans or animals Produce undesirable aquatic life.

Numeric Criteria Pollutants In-stream criteria metals, organics, etc. EPA list of pollutants subject BADT AKA “priority pollutants.” In-stream criteria pH, DO, chlorides, sulfates Based on human health and wildlife, for the intended use

What if the receiving waters are already more polluted than allowed for the intended use of the water?

TMDL’s Permit issuer (EPA or a few states) Determines that technology based standards will not achieve water quality standards pollutant specific Issuer develops “total maximum daily loads” (TMDL) of pollutant that water body can assimilate and comply with WQ standards.

TMDL refers to each toxic substance. Allocate TMDL to various point and non-point sources Might reserve for future development, or Account for scientific uncertainty

That is, all the NPDES permitees that discharge into the water can be limited. (They would have to limit their production or operations, or invest in better pollution protection equipment.)

Detail on Pretreatment Administered by POTW Subject to detailed regulations and oversight by EPA, NPDES regulators Purpose to avoid: “Pass-through” and “Interference”

Pretreatment Monitor significant industrial users Important general limitations hot material corrosive explosive health and safety of POTW workers Special limitations for certain industries ‘categorical limitations” Local limits

When writing the NPDES permit, the agency might specify that the contaminants be measured in the receiving waters, beyond some mixing zone.

Mixing Zone Compliance boundary 100 Meters is common zone of dilution before compliance with relevant WQ standard is measured 100 Meters is common Unless inappropriate exposures in MZ

Stormwater Foregoing was “point source” Stormwater is also often point source under-regulated by EPA until 1987 amendments to CWA now firmly regulated subject to varying deadlines Industrial vs. Municipal

Industrial Stormwater Broadly, stormwater Related to Industrial use Raw materials storage lists 11 major categories Including: 1. construction of more than 1 acre (had been 5) 2. landfills 3. recycling facilities

Industrial Applications Individual or Group application Must meet CWA criteria (called section 301) technology water quality based General Permits A general permit might be issued for an area, requiring less stringent administration.

Municipal Permits Similar to Industrial Municipalities must prevent non-stormwater discharges in storm sewers Reduce pollutants to maximum extent practical

Wetlands Section 404 of CWA not usually HW issue

SDWA and Groundwater All foregoing was CWA, discharges to fresh surface water. SDWA, Safe Drinking Water Act Deals primarily with tap water, what people drink. Not Hazardous Waste topic, usually

HW issues in SDWA Underground injection well, control Also Drinking Water MCLGs and MCLs maximum contaminant level goals maximum contaminant levels

Wells that inject hazardous waste are permitted.

Classes of Injection Wells I. Hazardous Waste injection below underground source of drinking water (with 1/4 mile) II. Industrial, oil and gas mostly, III. Certain mineral extraction IV. (old) HW with 1/4 mile of water source V. (old) Typically cesspools and drywells. See: https://www.epa.gov/uic/underground-injection-control-well-classes

Therefore Any discharge to groundwater that is not a permitted injection well is illegal

Class IV and V wells are being phased out Class IV and V wells are being phased out. Class II are mostly oil and gas industry putting drill cuttings and mud back into the hole. Class III are sulfur and salt extraction wells and similar processes.

Class I wells have many restrictions and many types of HW cannot be sent to a Class I well.

MCLG and MCLs These are numerical standards for drinking water that central water works pipe to residences. The recent flap about the arsenic standard was about an MCL. MCLs are valuable because they provide a number that one can argue is safe. So if a HW discharge to a pond will not drive the pond water over the relevant MCL, the polluter may argue that the pond water is “safe enough to drink.”

Discharges to marine (salt) waters come under different laws than fresh waters.

Marine Waters The “Ocean Dumping Act,” also known as Marine Protection, Research and Sanctuaries Act. No radiological, chemical, and biological warfare agents or high-level radioactive wastes may be dumped. Sewage sludge and industrial wastes were prohibited by an earlier act.

Ocean Dumping Dumping of other substances may be permitted by EPA Corps of Engineers may dump dredge spoil, but must notify EPA The muck that is dredged from rivers and harbors is often contaminated such that the dredged material is a hazardous waste.