Laurel Rognstad, TN Pretreatment Coordinator | May 15, 2019 • What is landfill leachate • Wastewater treatment process • Effects of leachate on WWTP • What is pretreatment/the pretreatment program • Leachate treatment • Miscellaneous discussion • Questions

• Formed when rain water percolates through landfill wastes and draws out contaminants • “Garbage Juice”

• What’s in the landfill? – Residential waste – Industrial waste – Commercial waste

• Landfills may contain: – Inorganics (no carbon) – Organics (carbon) – Heavy metals – Contaminants of Emerging Concern (CECs) • Pharmaceuticals • Personal Care Products • Household chemicals • Per- and poly-fluoroalkyl substances (PFAS)

• Factors affecting leachate quality: – Type and composition of wastes – Age of wastes – Climate and moisture composition of wastes – Waste processing and compaction and other landfill operational aspects – Temperature, pH, and redox condition in landfill – Presence of large quantities of municipal sewage sludge or industrial sludge or wastes – Thickness of refuse layer – Permeability, thickness, compaction, and slope of daily and final cover

Source: EPA’s Guidance Manual for the Control of Wastes Hauled to Publicly Owned Treatment Works

• Primary Treatment – Screening, grit removal – Physical process – Course solids • Secondary Treatment – Biological process (“activated sludge”) – Bacteria (bugs) used to break down organic matter in wastewater • Tertiary Treatment – only at some plants – “Final polishing” – Nutrient removal

• Wastewater treatments plants are designed to treat domestic wastewater (toilets, sinks, showers, laundry, etc) • Non-compatible pollutants and compatible pollutants in excess of the WWTP’s capacity can: – Interfere with or inhibit the biological process – Pass through into the receiving stream or sludge/biosolids • We don’t want to kill the WWTP’s bugs or pollute our lakes and rivers! • This is where the Pretreatment Program comes into play • Component of the NDPES Program and authorized under the Clean Water Act • Primary goal: to protect POTWs and the environment from adverse impacts that might occur when pollutants are discharged into a sewage system • EPA and authorized states (e.g., TN)) approve local municipalities to perform permitting, administrative, and enforcement tasks for discharges into the municipalities’ publicly owned treatment works (POTWs) 40 CFR 403.2 • To prevent the introduction of pollutants into POTWs which will: – interfere, – pass through, and/or – be incompatible • To improve opportunities to recycle and reclaim wastewaters and sludges

40 CFR 403.5 • To protect the POTW infrastructure • To protect POTW workers

Limitations on Sludge Disposal Options and/or Injury to Workers Greater Expense from Hazardous Fumes

Corrosion of Collection System and/or Treatment Plant

Explosions

Interference with Wastewater Pass-Through of Treatment Facility Toxics into Surface Waters

• Authority is delegated to approved local programs (i.e., municipalities and utilities) • Over 100 active approved pretreatment programs in TN accept wastewater from over 700 permitted industries – Wide variety of waste from a wide variety of industries, such as dairy, prosthetics, batteries, automotive, pharmaceutical, electroplating, meat processing, and…landfill leachate • A city/utility is required to have pretreatment program if a Significant Industrial User (SIU) • An SIU is defined in 40 CFR 403.3(v) as any of the following: – An IU subject to federal categorical pretreatment Not applicable standards to landfills – An IU that discharges an average of 25,000 gallons per day (gpd) or more of process Maybe wastewater to the POTW – An IU that contributes a process wastestream making up 5 percent or more of the average Maybe dry-weather hydraulic or organic capacity of the POTW treatment plant – An IU designated by the POTW as such because of its reasonable potential to adversely affect the Maybe POTW's operation or violate any pretreatment standard or requirement.

• Inspections • Sampling – Sampling by city – Self-monitoring requirements • Permitting – Subject to effluent limits, & self-monitoring, sampling, reporting, notification, and record-keeping requirements • Enforcement – Such as NOV, Compliance Order, civil & criminal penalties, termination of service • TDEC is responsible for oversight of local pretreatment programs – Ensure programs are properly implementing and enforcing pretreatment requirements

• Chattanooga Moccasin Bend WWTP – 140 MGD design flow rate – Discharge to Tennessee River (min. low flow varies from ~2000 to ~8000 MGD dependent on TVA operations) • Pikeville WWTP – 0.254 MGD design flow rate – Discharge to Sequatchie River (7Q10 low flow = 3.28 MGD) • Not “one size fits all” • All pretreatment programs are different – Different limits – Different surcharge rates – Different inspection and sampling frequencies – Different capabilities to accept waste (such as LFL) • Capacity (hydraulic and organic – moratorium status?) • Operations/Management • Efficiency of WWTP • Receiving waters • Who decides? – Not TDEC (unless we know leachate is causing major issues) • The “big” issue • Inhibition/pass through

(4) U.S. EPA. 1986, Working Document; Interferences at Publicly Owned Treatment Works. September 1986. • Source of nitrogen • More and more POTWs getting nitrogen limits • Nutrient reduction at POTWs (P & N) – Harmful algal blooms – Hypoxic zone (“dead zone”) in Gulf of Mexico • Ammonia source reduction (tighter limits/no discharge)

Source: NOAA Source: DISCLAIMER: I’m a regulator, not a consultant or leachate treatment expert…

• Equalization • Aeration • Biological treatment • Multimedia filtration • Chemical precipitation • Air stripping • pH adjustment • Coagulation • Ion exchange • Carbon adsorption • Flow control (not treatment, but it can help!)

• No pretreatment program? – 40 CFR 122.42(b): POTWs with NPDES permit must notify the NPDES permitting authority when there is: • Any new introduction of pollutants into the POTW • Any substantial changes in the volume or character of pollutants – Applicability of SIU definition • Some Other Options – Apply to direct discharge (NPDES permit) • Subject to effluent guidelines under 40 CFR 445 • Likely much greater treatment requirements • Likelihood of getting permit?... – Send to Centralized Waste Treatment (CWT) facility • $$$