1. Drinking Water & Wastewater Regulation and Treatment

2. Drinking Water Regulations
Interstate Quarantine Act
Result: Prohibition of Common Drinking Cup on Interstate Carriers – created a market for Dixie® cups
Microbiological Standard
2 coliforms / 100 ml
New Microbiological Standard
1 coliform / 100 ml
Maximum Concentrations for Constituents:
Lead Fluoride Arsenic
Selenium Barium Hexavalent Chromium
Copper Magnesium Iron + Manganese
Zinc Chloride Sulfate
Phenolics* Total Solids Alkalinity
*Phenol = carbolic acid, addition of methyl group forms cresols, o, m, or p

3. Drinking Water Regulations
1962 Limits for:
Alkyl benzene sulfonates (synthetic detergents)
Carbon-chloroform extract (organic residues)
[Adsorption on activated carbon, chloroform extraction, gravity quantification]
Barium Cadmium Cyanide
Nitrate Silver Radioactivity
Safe Drinking Water Act of 1974
Enacted over concern about organic materials in drinking water
Established Maximum Contaminant Levels (MCLs) for several substances [Enforceable]
Federal Guidelines - Secondary MCLs (SMCLs), [Nonenforceable]

4. 1975 - National Interim Primary Drinking Water Regulations
Amended repeatedly, now include:
Microbiological Contaminants
Total and Fecal coliforms, E. coli, Turbidity
Radioactive Contaminants
Beta/photon emitters, Alpha emitters, Combined radium
Inorganic Contaminants
15 elements or materials
Synthetic Organic Contaminants including Pesticides and Herbicides; Volatile Organics
54 compounds and groups of compounds

5. Drinking Water Treatment

6. Groundwater Treatment Options

7. Surface Water Treatment Options

8. Drinking Water Treatment Units or Processes
INTAKES
AERATION
COAGULATION & FLOCCULATION
CLARIFICATION
FILTRATION
DISINFECTION
SOFTENING
TASTE & ODOR CONTROL
IRON & MANGANESE REMOVAL
TRACE METALS & ORGANICS

9. AERATION (Usually for Groundwater)
ADDS OXYGEN
REMOVES:
Carbon Dioxide Hydrogen Sulfide
Methane Taste & Odors
REMOVAL MAY BE BY:
Oxidation Volatilization
Iron & Manganese Organics

10. Coagulation, Flocculation & Clarification
Coagulation changes the electrical charge of suspended particles and colloids; allows attachment to each other. Coagulants are usually cations: Alum, Ferric Sulfate, Lime (CaO)
Chemical/Physical process of mixing special purpose chemical from flow and removing the resulting product
Silts/Clays, Viruses, Bacteria
Fulvic & Humic Acids, Minerals, Organic Particulates
Flocculation is the agglomeration of particles into settleable particles
Clarification - sedimentation of floc particles, allows longer filter runs, settling velocity of the floc allows particle removal before the water leaves the basin

11. Drinking Water Filtration
Rapid Sand Filters are most commonly used for surface water
May be gravity or pressure flow
Some States prohibit pressure flow
Fine-to-course (back wash result)
Course-to-fine (multi-media)
Anthracite, Sand, Course Garnet, Fine Garnet
Rapid Sand filters may clean gpm/ft2
Alternatives include: microscreens, diatomaceous earth filters, cartridge filters

12. DISINFECTION CT concept is the current basis for disinfection theory:
CT = K
C = disinfectant concentration
T= contact time
K= proportionality constant, variable with different organisms
Ohio regulation = 30 min contact time, 0.2 mg/l Cl2 residual
Chlorination is most common in the U.S.
Effective, low cost, proven technology
Reactions with natural aquatic organics produce trihalomethanes -- suspected carcinogens
Ozonation is popular in France, Germany, Canada, and Russia
Chlorine Dioxide gaining acceptance in Europe and U.S.

13. Chlorine Chemistry Cl2 + H2O -----> H+ + Cl- + HOCl
HOCl = Hypochlorous Acid, is the most active ingredient, concentration is pH dependent; dissociates to: H+ + -OCl
Active against (listed in decreasing order):
Bacteria Viruses Protozoans (cysts)
Chlorine reacts with Ammonia (NH3) to produce mono, di, and trichloroamines
NH2Cl NHCl2 NCl3

14. Chlorine Residuals & Chlorine Demand
Free Chlorine: Cl2, HOCl, -OCl
Combined Chlorine: Chloramines
Free Chlorine has strong disinfecting powers but is quickly dissipated
Combined Chlorine is slower acting but remains in solution longer and provides longer-term protection
Chlorine Demand = the difference between the amount of chlorine applied and the amount of free, combined, or total chlorine remaining at the end of the contact period
Anything oxidizable can produce a chlorine demand, including pathogens, organics, particulates, sulfides, ammonia, etc.

15. Alternative Disinfectants
Ozone
O3, powerful oxidant, alternative to chlorine
Effective at low doses
Expensive (capital and operating costs)
Produces no residual
Chlorine Dioxide
ClO2, an unstable gas, produced at the point of use from sodium chlorite, NaClO2
Nearly as effective as chlorine, does not react with ammonia to produce chloramines, or with other organics to form trihalomethanes

16. BIOFILMS
In many environments, microorganisms form, and exist in, complex, protective layers called biofilms
Biofilms may form in any part of a drinking water distribution system. Cooling towers can support robust biofilms.
Disinfectants may be unable to attack or completely remove the organisms in biofilms
Most biofilms are made up of non-pathogenic organisms; however, pathogens may be protected in such an environment

17. Softening
Reduction in dissolved calcium and magnesium reduces deposits in distribution system - scale formation (CaCO3)
Hard water reacts with soap to form films that are difficult to remove
Hard water deposits form scale in boilers
Softening also removes some trace inorganics – Pb, Cd, Ag, Ba, Cr, As, Hg, and Ra
Lime-soda process adds quick lime (CaO) or hydrated lime [Ca(OH)2], precipitating calcium carbonate (CaCO3)
Ion-exchange removes Ca2+ and Mg2+ and replaces them with Na ions; often used in homes

18. Taste & Odor Control
Very low concentrations of metals, salts, or organics may produce detectable levels in sensitive people - iron, copper, manganese, and zinc, magnesium chloride and bicarbonate, chlorinated organics; fungal and algal metabolites; hydrogen sulfide, other sulfur compounds
Activated carbon is often very effective in removing organics
Oxidation (chlorine, chlorine dioxide, ozone)

19. Iron & Manganese Removal
Iron and manganese cause staining and leave noticeable residuals at very low concentrations
Fe >0.2 mg/l Mn >0.1 mg/l
Iron promotes growth of “iron bacteria” in mains that increase friction and power consumption
Oxidation produces less soluble compounds and precipitation is often used for removal
Trace Metals
Iron, Cadmium, Lead, Copper, Zinc may come from the plumbing system; others may be from the aquifer
Corrosion control processes may be the most effective means of reducing these concentrations - precipitation of a layer of calcium carbonate often provides a nonreactive surface

20. Solvents, hydrocarbons, etc. may come from the aquifer
Turbidity
A measure of suspended particulates in water - clays, microorganisms, organics
Highly turbid waters are difficult to disinfect because of high demands - large amounts of materials to be oxidized; organisms protected from exposure to disinfectants
Coagulation and flocculation, and filtration are common removal methods
Trace Organics
Solvents, hydrocarbons, etc. may come from the aquifer
Modified organics may be the result of disinfection processes
Humic and fulvic acids are poorly defined and are common in natural waters
TOC and TOX are broad tests of water quality
Precipitation, filtration, adsorption, and oxidation may all remove some of the materials

21. Fluoridation
The fluoridation process was very controversial when initially implemented
Low concentrations (1 - 2 mg/l) of fluoride provide strong protection against tooth decay
Slightly higher concentrations (> 4 mg/l) can cause discoloring of teeth

22. CROSS CONNECTIONS FOAMING AGENTS
Accidental contamination of drinking water can occur during routine plumbing modification, sewer backups, floods, earthquakes, careless homeowners, etc.
FOAMING AGENTS
Surfactants (the active part of detergents) can get into surface water through incomplete sewage treatment
Groundwater sources include septic tank systems

23. Nitrate & Nitrite Nitrate is common in natural waters at 1 to 2 mg/l
Nitrate (NO3) is reduced to nitrite (NO2) in the digestive system - reduction is more complete in infants than adults - because of more alkaline conditions in system
Excess nitrite produces methemoglobinemia in infants by oxidizing hemoglobin to methemoglobin which cannot carry oxygen
Nitrosamines formation (suspected carcinogens) can also occur from nitrate or nitrite

24. TOTAL DISSOLVED SOLIDS
High TDS may increase corrosivity because of increase conductance
High sodium may be of health concern
CORROSIVITY
Decreases life of plumbing system
Solubilized metals, perhaps in toxic quantities - lead and cadmium are of most concern
Copper, iron, and zinc produce tastes and stains
Corrosion can shield microorganisms from disinfection processes
Water may be characterized as passive or aggressive

25. CLEAN WATER ACT - Background
Rivers and Harbors Act of 1899
Prohibited discharge of refuse without a permit from the Secretary of the Army
Water Pollution Control Act of 1948
Gave primary responsibilities to the States
Provided construction funds, Money never appropriated
Water Pollution Control Act Amendments of 1956
Authorized Grants for construction
Provided funds for research into Health Effects
Other minor Acts in 1961, 1965, 1966, 1970

26. Federal Water Pollution Control Act - 1972 - PL 92-500
Goal of “fishable/swimmable” water
Construction Grants for Sewage Treatment Facilities
BPT - Best Practicable Treatment
BAT - Best Available Treatment
Concentrated on Oxygen Demand, Suspended Solids
NRDC v. Train - Consent Decree - resulted in...
Clean Water Act PL
Wetlands Resources Act
Water Quality Act Amendments of 1987
Required EPA regulations on storm water runoff
Required State nonpoint source management programs

27. TITLE I -RESEARCH AND RELATED PROGRAMS
Sec Declaration of Goals and Policy -- Objective: Restore and maintain the chemical, physical, and biological integrity of the Nation's waters.
Goals:
1. Eliminate pollutant discharges into navigable waters by 1985.
2. Interim goal to protect fish, shellfish, and wildlife and provide for recreation in and on the water by July 1, 1983.
3. Prohibit the discharge of toxic pollutants in toxic amounts.

28. TITLE III - STANDARDS AND ENFORCEMENT
304 - Information and Guidelines - provides for development of water quality criteria. Defines conventional pollutants - including, but not limited to, biological oxygen demand, suspended solids, fecal coliforms, and pH, --- specifically excluded thermal.
305 - Water Quality Inventory - requires States to provide a water quality description, an inventory of point-source dischargers, and an estimate of costs of improving quality.
306 - National Standards of Performance - requires a list of categories of sources and establishment of new source performance standards for those categories

29. TITLE IV: PERMITS AND LICENSES
Sec National Pollutant Discharge Elimination System - (NPDES) establishes requirements for issuing permits and State implementation of the program.
Excludes: Irrigation return flows, Storm water runoff from Oil, Gas and Mining operations
Anti-Backsliding - renewed permits must be as stringent as the original
Storm water is included by October 1, 1993

30. ADDITIONS, AMENDMENTS
LIMITATIONS ON DISCHARGE OF RAW SEWAGE BY NEW YORK CITY
North River Plant - required to have advanced preliminary treatment by Aug, 1986
Red Hook Plant - required advanced preliminary treatment by Aug, 1987
BOSTON HARBOR AND ADJACENT WATERS
Authorization for constructing waste treatment works for providing secondary treatment

31. Oil Pollution Act Revised penalties for oil discharges
Administrative penalties of $125,000 for violations of regulations or discharges
Civil penalties of $25,000/ day for discharges, or $1,000/ barrel of oil
Gross negligence or misconduct minimum penalty of $100,000

32. CONVENTIONAL POLLUTANTS
Several are “Empirical,” derived by experimentation
Biological Oxygen Demand - test using microorganisms that measures oxygen uptake over five days
Suspended Solids - quantified by filtration of a sample and drying and weighing the filter
Fecal Coliform Bacteria - microbial analysis dependent upon incubation conditions and selective media
pH - measured directly
Oil and Grease - derived by extraction of a water sample with a solvent and either an infra-red (IR) measure of the solvent, or a gravimetric measure of the residue

33. Pretreatment Regulations
Industrial discharges into POTWs (40 CFR 403)
POTWs with flows > 5 million gpd, or smaller POTWs with significant industrial discharges must establish local pretreatment programs
National standards must be enforced
Hazardous wastes are the focus of regulation
Significant industrial users must meet reporting requirements:
Users subject to categorical pretreatment standards
Users of > 25,000 gpd of processed wastewater
Users that make up >5% average organic capacity
Other users with a reasonable potential to adversely effect the POTW’s operation

34. Wastewater Treatment Collection System Sewage Stormwater
Domestic (sanitary)
Industrial
Mixed
Stormwater
Separate Systems
Combined Systems
Infiltration (20 to 3,000 gal/acre/day)

35. Unit Operations & Unit Processes
Unit Operations - Treatment methods using physical forces
Screening Mixing Flocculation
Sedimentation Flotation Filtration
Aeration (gas transfer)
Unit Processes - Treatment methods using chemical or biological reactions
Precipitation Adsorption Disinfection
Biodegradation Nutrient Removal

36. Treatment Levels
Primary Treatment - (preliminary), physical unit operations
Removal of constituents that cause maintenance or operational problems -- debris, grit, oil and grease,
Secondary Treatment - chemical and biological unit processes
Removal of biodegradable organics and suspended solids
Tertiary Treatment - (advanced), combinations of all three methods
Removal of residual nutrients, toxics, specific contaminants

37. Typical Treatment Process
Bar Grit
Influent Screen Chamber Primary
Clarifier
Anaerobic Activated
Digester Sludge Unit(s)
Disinfection Secondary
Effluent
Sludge
Disposal
Sludge
Return

38. Industrial Wastewater Treatment - Differences
Equalization - hydraulic residence time at least equal to activated sludge unit, may be several times longer
Oil Separation
Dissolved Air Flotation, Dissolved Gas Flotation
Corrugated Plate Interceptors
Sludges may be hazardous by regulation

39. Design Criteria Flow Rate Mass Loading Peak Hour Maximum Day
Maximum Month Minimum Hour
Minimum Day Minimum Month
Mass Loading
Maximum Day Sustained Peaks
Maximum Month Minimum Month
Minimum Day

40. Wastewater Daily Flow Pattern
Midnight Noon Midnight

41. Reactor Types Homogeneous Reactions: Batch Reactor Plug-Flow Reactor
Complete-Mix Reactor, Stirred Tank Reactor
Complete-Mix Reactors in Series -
May be significantly more effective than the same volume in a single unit
Arbitrary -Flow Reactor
Heterogeneous Reactions:
Packed-Bed Reactor
Fluidized-Bed Reactor

42. Mass-Balance Analysis
Accumulation = Inflow - Outflow + Generation
V dC/dt = QCo - QC + V(-kC)
V = volume of reactor
dC/dt = rate of change of reactant concentration within reactor
Q = volumetric flow rate into/out of reactor
Co = reactant concentration in influent
C = reactant concentration in reactor and effluent
k = first-order reaction-rate constant
Mass Balance Applications
Model constituent biodegradation or removal (volatilization, precipitation, etc.)
Model solids (sludge) formation

43. Common Operational and Design Practices
Gravity flow through system
Only pump the water one time
Parallel units
Allow operational flexibility and maintenance
Minimize human contact with materials

44. SIMPLIFIED TREATMENT FLOW Fairborn Plant
Raw
Sewage
Grit
Tanks
Oxidation
Ditches
Digesters
Landfill
Sludge
Return
Disinfection
Clarifiers
Effluent to
Mad River

45. Fairborn NPDES Permit Requirements
Sampling Stations
Plant Outfall
Waste Sludge
Raw Sewage Influent
Upstream at State Route 235
Downstream ft south of lift station at River Mile 8.6
Samples:
Composite samples of at least three grab samples proportionate in volume to the sewage flow rate at the time of sampling...intervals of at least 30 min., but not more than 2 hours

46. Fairborn Performance Statistics
Average Daily Flow (mgd)
Average Influent:
Suspended Solids mg/l
BOD mg/l
Ammonia mg/l
Average Effluent:
Suspended Solids 6 mg/l 97%
BOD mg/l 98%
Ammonia mg/l 99%