CEE 463 Final

Environmental Audits

systematic, documented, periodic, and objective review of the operations and practices used to meet environmental requirements

Compliance Audits

objective is regulatory compliance and verification of compliance with regulations; Is the operation in compliance? Identifying violations

Management Audits

Is there an adequate compliance management system in place, implemented, and utilized so that environmental compliance is integrated into daily operations

Liability definition audits

completed for prospective real estate buyers and for proposed mergers and acquisitions; identify environmental problems that could affect property values; risky not to conduct in real estate and acquisitions

Waste contractor audit

used to analyze commercial facilities that store, treat, and dispose of hazardous waste

Risk definition audit

involves analysis of the operations of facilities that handle hazardous materials and substances; materials and substance; can support obtainment and maintenance of insurance coverage, might be required

Waste minimization audits

examination of the waste generated by a facility; objective to identify sustainable actions and reduce the quantity and toxicity of the waste generated

Stage 1

Audit program planning with objectives and scope

Stage 2

Preaudit preparation that includes pre-visit data collection (this facilitates open-ended audit process and continuous improvement)

Stage 3

On-site activities

Stage 4

Evaluation of the audit data and reporting of findings

Audit and Self-reporting

Audit found miscalculated information for 3 prior years regarding the chemical release report

Outside consulting firm conducted audit

Facility self-reported violations and made corrections

$2000 fine

No audit and EPA Inspection

EPA inspection of a facility revealed information for one chemical was substantially mis-reported

$60,000 fine

Waste minimization

any management technique or process modification that reduces mass or toxicity of waste that will be treated and disposed of

Pollution prevention

includes managing chemical to reduce risk, identifying and estimating all releases, and waste minimization

POLLUTION PREVENTION- INCENTIVES

3M’s Pollution Prevention Pays program is an example of an economic

incentive

 Legal and regulatory incentives

 RCRA

 Emergency Planning and Community Right-to-Know (EPCRA) of

Superfund Amendments and Reauthorization Act of 1986 (SARA)

 Industries must provide info on toxic waste releases to local communities

 1990 Pollution Prevention Act- established national pollution prevention

strategy, provided grants to states to promote source reduction, and

established a source reduction clearinghouse

 33/50 voluntary program with national goal of 50% reduction in

generation of 17 high priority toxic chemicals by 1995 was successful

(750 million lbs of the 17 chemicals were reported, less than 1.5 billion

lbs reported in 1988)

 Recent legislation focuses on PFAS chemicals, industrial waste, and

managing plastics

 EPA’s 2025 PFAS reporting rules in the Toxics Release Inventory

STRATEGIES FOR ACHIEVING WASTE MINIMIZATION

Audits aid in waste minimization/4 Stages of

Waste Reduction

1. Common sense waste reduction- immediate

opportunities with no change in production

processes. How much water is used for

cleaning?

2. Information-driven waste reduction- easy

opportunities from simple changes in

production. Can you change a raw material?

3. Audit-dependent waste reduction-

opportunities that require capital investment and

production changes. Is the ROI worth it?

4. Research and development waste reduction-

opportunities that face several obstacles and

require extensive research to overcome

Life Cycle Analysis

Analytical framework for investigating the range of environmental impacts

Volume Reduction

accomplished via modifying production processes, segregation, and reuse

Toxicity Reduction

accomplished via modifying processes and/or equipment, and good housekeeping

Facility

contiguous land, structures, and other improvements used to store, recover, recycle, treat, or dispose of hazardous waste

On-site facilities

constructed and operated by generators at their own location (e.g. Rotary kiln incinerator onsite

Off-site facilities

specialized facilities for treatment and disposal where generators transport their waste

recovery/recycling facilities

recover material as product that can be sold (solvents, oils, acids, or metals) or energy value (e.g cement kilns)

Treatment facilities

physical, chemical, thermal, or biological methods are used to change the physical or chemical characteristics of the waste; degrade or destroy waste constituents

Land disposal facilities

permanent placement of waste on or below land surface after treatment; must meet defined standard for land disposal

Recovery solvent

Separate contaminants from waste solvents

• Results in original or lower-grade solvent product

• Distillation results in 75% recovery

Recovery Oils

Recovery of used lubricating oils

• Oil refining via the acid/clay method or distillation

(more costly)

• Distillation preferred, because acid/clay results in

spent acidic oily clay residue

Recovery acid regeneration

Separation of unreacted acid from and acid waste

Recovery Metals

Pyrometallurgy uses difference in melting and

boiling properties to separate metals at high

temperatures

• Hydrometallurgy extracts and concentrates

metals from liquid waste using ion exchange,

electrodialysis, reverse osmosis, membrane

filtration, adsorption, sludge leaching,

Fuels blending

Waste fuels comprised of waste oils, solvents and distillation bottoms by blending wastes or mixing with

coal or fuel oils

• Separation and hydration pretreatment processes used for treatment of oils

Coincineration with kilns/furnace

Cement, light aggregate, and some other product manufacturers us a special type of rotary kiln

• Coincineration with primary fuels and raw materials in industrial kilns (2600 to 3000°F)

• Waste is a supplementary fuel

Thermal destruction

PFAS requires 1500°F for thermal

destruction

Waste exposed to high temperatures in the

presence of oxygen

Partial or complete destruction of organic

waste

Incinerator is an example

RCRA regulations state that destruction

(DRE) must be achieved and removal

Aqueous destruction

Cyanide waste > pH adjustment > reactor

with oxidant added and release of metal

hydroxide sludge > effluent or additional

treatment

For removal of hazardous wastes dissolved

or suspended in water

Similar to wastewater treatment- selection

and sequence of treatments based on

characteristics of hazardous waste and

required effluent quality

Stabilization

Haz waste mixed with Portland cement, fly

ash, or lime

Mixing materials with wastes to improve the

handling and physical characteristics and

reduce mobility of contaminants

Typically, in a landfill

Chemical binding of the waste that results in

low solubility or a chemical change to make

the waste insoluble

Biologic treatment

Use of microbes to degrade organic wastes

Organics are mineralized or transformed into

lower molecular weight compounds

Considerations are biomass/microbes,

moisture content of waste, and degree of

aeration

Landfill

Permanently placing hazardous waste

• Pretreatment (e.g. stabilization) before placement for land disposal

• Regulations define the amount of pretreatment necessary

• Placement in shallow trenches, mounded cells, or vaults mostly above grade

• Landfills will have liners for containment, minimize leachate, and remove leachate generated

• Operated as containment facilities

Deep Well Injection

• Injection of liquid waste into a deep, porous subsurface formation containing salt water

• The subsurface geological formation is below potable aquifers and should have an impermeable confining layer

above it

Other land disposal

Surface impoundments can be used to retain liquid waste and sludges

• Liners are also used here

• Land applied, pretreated biological waste/sludge

1. PRESHIPMENT WASTE ANALYSIS

Waste analysis plan- specifies parameters for analysis,

sampling and analytical methods, frequency of analysis

• Waste profile

• Representative sampling of a waste shipment is conducted

on arrival at a facility

• Determine if the waste can be accepted by the facility

• Identify the inherent hazards of the waste

• Determine physical characteristics and chemical

constituents of the waste– best processing, treatment,

and disposal methods

• Select verification parameter to be tested on arrival

• Develop a cost estimate for treatment and disposal

2. WASTE RECEIVING

Upon acceptance of the waste, the manifest is signed and a

copy is sent to generator- liability is shared with facility and

generator

 Scheduled shipments go to receiving station- what about

unscheduled shipments?

 Analysis of representative samples

 Upon verification of of the waste shipment, the waste goes to

the unloading area to be emptied

 Vehicles are reweighted before leaving the facility

 Vehicles may be decontaminated

3. WASTE STORAGE AND PREPARATION

After unloading, the waste

goes to storage

 Tanks or impoundments for

liquids

 Hoppers for solids and

sludges

 Pads and warehouses for

containers

Store the waste safely before treatment

and disposal– ensure compatibility

(storage material and other wastes)

2. Provide adequate accumulation time

when treatment and disposal systems

are not in service

3. Facilitate mixing, blending, and

repackaging of waste as needed

4. Allow staged input of wastes with

reagents for subsequent treatment

4. TREATMENT

Treatment schedule is developed while the

waste is being stored

 Waste to be treated

 Storage location

 Necessary preparation for treatment

 Method of treatment

 Rate at which the waste is fed for treatment

5. RESIDUALS

Waste treatment produces

gas emissions, effluents,

and residuals

 These products require

management

Special measures

Security

 Inspection and maintenance

 Incident prevention

 Emergency planning

 Employee training

 Safety

 Monitoring

 Reporting

 Record-keeping

 Audits

FACILITIES CLOSURE

Closure plan is needed to pose a minimal risk to the environmental and human health and requires

minimal post-closure maintenance

Requires removal of all remaining waste to another facility; except for landfills

Landfill closures require waste to be contained (e.g. cover systems and long-term post-closure plan for

managing leachate, monitoring maintenance, security, and other measures for at least 30 years or

longer.

Funds must be available to close the facility, based on a cost estimate that is part of the closure plan

EPA requires that the cost estimate must equal the maximum costs of closing all waste management

units ever activated at the facility

FACILITIES- NEEDS ASSESSMENT, SITE SELECTION, PUBLIC

PARTICIPATION, PERMITTING

Current and future types and quantities

of hazardous wastes generated that

would be managed at the proposed

facility

2. Current methods for managing these

wastes

3. Methods expected or desired in the

future for managing the generated waste

4. Capacity of existing facilities providing

such methods

New facilities should be

located at better sites

based on

 natural features and land

use

 High degree of

protection to public

health and environment

Site screening methods

Intuitive- decision maker examines all data as a whole and judges whether the site is acceptable

 Stepped down exclusive- examines each siting factor sequentially, determines criterion (definitive threshold of acceptability) for the factor, and applies

the criterion to eliminate areas from further consideration

 Scaling- one of weighting the site data; data are modified from their original form by replacing them with numerical surrogates having a common scale

 Criteria combination- use either the stepped-down exclusion or scaling technique; alternatives are developed

Siting criteria

stem from siting factors associated with a specific consideration important in judging the suitability of a site

 Criterion- definitive threshold of acceptability for a siting factor (e.g. criterion for permeability (hydraulic conductivity) could be a maximum of 1X10-7

cm/s)

 Mandatory criteria- represent a legal requirement, a regulatory standard, or some other aspect deemed so important that it cannot be violated for any

reason

 Discretionary criteria- represent desirable, but not mandatory features, and include preferences and value judgments.

Consider value judgments and tradeoffs

acceptable risk; never zero risk

Permitting

is the action of regulatory

agencies to authorize construction and

operation of a facility

• Facilities must have a valid permit to

operate

• Hazardous waste facilities are some of

the most closely regulated

AIR STRIPPING

Mass transfer process to enhance volatilization of compounds from the liquid phase (water) into a vapor phase (air).Cost-effective in removing volatile organic compounds (VOCs) from water Commonly used to remediate VOC-contaminated groundwater, and it is most effective for low concentrations of VOC (less than 200 mg/L). Stripping basins or towers are used:

 Basins consist of diffused aeration or mechanical aeration (aeration basins)

 Towers consist of packed towers, trayed towers, and spray systems

Air stripping limitations

Now the contaminant is in the vapor phase

The air may require further treatment

Fouling is common due to iron oxidation, growth of

algae, bacteria, fungi, or particulates in the water

Pretreatment may be needed to minimize fouling

Why is air stripping useful

Cost-effective in removing volatile organic compounds (VOCs) from water.

Good for handling haz waste with solids or the potential for clogging (no media)

SUPERCRITICAL FLUIDS

Advanced technologies using fluids above critical temperatures/pressures

Materials at elevated temperature and pressure that have properties between those of a gas and a

liquid

 Supercritical fluids extraction (SCF/SFE)- uses carbon dioxide for extracting compounds; Organics in

soils, sediments, or water are dissolved in the fluid at elevated temperature and pressure conditions and

released from the supercritical fluid at lower temperatures and pressures.

SUPERCRITICAL FLUIDS Limitations

High costs

 Energy use

 Corrosion and clogging- inorganic salts are insoluble in supercritical water and the preciptates can cause clogging,

and acidic products in hazardous waste can cause corrosion

 Specialized materials and design of systems

REVERSE OSMOSIS

Removes dissolved constituents

Uses preferential diffusion for separation

Semipermeable membrane (thickness less

than 1 mm)

Permeate- clean flow

Concentrate-retentate, brine, reject water

Why reverse osmosis is helpful

EPA considers reverse osmosis a best available

technology for removing many inorganic

contaminants– radionuclides, arsenic, nitrate, nitrite

 Effective for removal of pesticides

Reverse osmosis limitations

Disposal of brine/waste feed

 Less cost-effective treatment