FEM Glossary – Index

A | B C D | E F | G | H | I | J | K L | M | N O | P | Q | R | S | T U | V W | X | Y | Z
TermsDescription of termsSourceReference
Absolute reductionsReduction in actual utility consumption (e.g. kWh of electricity used, or cubic meter of water used for the whole facility within a calendar year) or pollution generated (e.g. kg of hazardous waste for the whole facility within a calendar year) regardless of facility size, production volumes, production hours, raw material usage or other business metrics.Higg Index 
Air emission inventory

An inventory of emissions to air is a detailed list of the emissions and their sources, it should include the following information for each emission source:

  • the pollutants known or likely to be present;
  • the quantity emitted (if known or estimated);
  • the location of, for example, the stack, vent etc.;
  • any control devices (e.g. abatement equipment) installed;
  • frequency of monitoring; and
  •  whether the particular emission is legally regulated.
Higg Index 
Air pollution controlAir pollution control refer to steps taken to maintain a standard of purity of air for good public health; for protection of plant and animal life, and property; for visibility; and for safe ground and air transportation.OECDLink
All waste streamAll waste stream means all the wastes produced on-site including wastes generated from manufacturing the product, office use, waste produced by workers at the canteen, dormitory, and waste produced by contractor coming on-site to perform a service.Higg Index 
Alternative assessmentIt is a process for identifying alternatives (chemical or non-chemical) to a chemical of concern, screening out equally or more hazardous alternatives, and selecting an alternative that is technically and economically viable and does not have the potential for causing significant environmental or human health impacts.OIA – Chemicals Management Framework Glossary 
BarriersAny coatings and/or laminations used on textiles or footwear products. Barriers may be bicomponent (two or more materials), microporous (material with pore diameters of less than 2nm) or monolithic (single covering without seams or joints).Higg Index 
BaselineBaseline is the initial metric for the utility use to be improved from.  The initial metric is the beginning measure taken to establish a stable starting point to evaluate improvement against. It must reference a specific timeframe from which the baseline was calculated, typically annual consumption.  Identifying any unique variables makes the metric more accurate.Higg Index 
Biological oxygen demand (BOD)Biological Oxygen Demand (or Biochemical Oxygen Demand) (BOD) is an indicator of the level of organic matter in the water and, hence, the rate at which oxygen in the water is used up as the organic matter is consumed by organisms in the water. Generally, the lower the BOD, the better the water/ wastewater quality.Higg Index & GSCP 

Biomass is biological material from living or recently living organism. Sustainable biomass sources are:

• Energy crops that do not compete with food crops for land; high yield crops grown specifically for energy applications.

• Agricultural residues: residues from agriculture harvesting or processing, such as wheat straw or rice husk.

• Sustainably-harvested wood and forest residues.

• Waste wood

Higg Index 
Brackish surface water/seawaterBrackish water is water in which the concentration of salts is relatively high (over 10,000 mg/l). Seawater has a typical concentration of salts above 35,000 mg/l.CDP Water Reporting GuidanceLink
CAS numberCAS Registry Numbers (often referred to as CAS RN® or CAS Numbers) are universally used to provide a unique, unmistakable identifier for chemical substances. A CAS Registry Number itself has no inherent chemical significance but provides an unambiguous way to identify a chemical substance or molecular structure when there are many possible systematic, generic, proprietary or trivial names.CASLink
Chemical oxygen demand (COD)Chemical Oxygen Demand (COD) is an indicator of the level of organic matter and chemicals in the water and, hence, the rate at which oxygen in the water is used up as the organic matter and chemicals are consumed. Generally, the lower the COD the better the water/ wastewater quality.GSCP 
Circular economyA circular economy is an alternative to a traditional linear economy (make, use, dispose) in which we keep resources in use for as long as possible, extract the maximum value from them whilst in use, then recover and regenerate products and materials at the end of each service life.WRAPLink
Climate changeClimate change refers to any long-term change in Earth’s climate, or in the climate of a region or city. This includes warming, cooling and changes besides temperature.NASALink
Domestic waterWater consumed for non-industrial purposes within the facility, such as drinking water, flush water.Higg Index 
Emergency Response Plan (ERP)An Emergency Response Plan is a plan of action for the efficient deployment and coordination of services, agencies and personnel to provide the earliest possible response to an emergency.WREMLink
Energy (indirect)Energy (indirect) can be purchased from public and private utilities in the form of electricity, steam, or heat.Higg Index 
Energy carrierSubstance or phenomenon that can be used to produce mechanical work or heat or to operate chemical or physical processes.ISOLink
Environmental Management System

A management system is a set of interrelated elements used to establish policy and objectives and to achieve those objectives.

An environmental management system must consist of:

a. Environmental Policy

b. Planning: environmental risk assessment, setting objectives and targets

c. Implementation and operation: operational procedures; adequate training; documentation and its control

d. Checking: monitoring and measurement, audit and inspections

e. Management Review

GSCP, Higg Index based on ISO14001:2004 
Environmental policyThe policy describes the site’s activities, products, and services including a commitment to continual improvement and prevention of pollution, as well as a commitment to comply with legal and other requirements that relate to the significant environmental aspects identified for the site. The policy should set out the framework for setting and reviewing environmental objectives and targets.Higg Index 
Final disposalFinal disposal means the final step to transform or destroy your waste.  If your contractor is only collecting your waste and selling it to another company, the final disposal will be the last company that handle your waste by recycling or incinerating or treating (physical or chemical treatment) or landfilling your waste. This can be controlled in the factory by checking the waste collection area and confirming that sorting is well-managed.Higg Index 
FoamsA solid “open cell” or “closed cell” foam material commonly used in packaging and footwear. Includes EVA, PE, and PU foam.  
Fossil fuelsFossil fuels are coal, oil and natural gas. They are derived from the remains of ancient plant and animal life.OECDLink
Fresh surface waterSurface water is naturally occurring water on the Earth’s surface in ice sheets, ice caps, glaciers, icebergs, bogs, ponds, lakes, rivers and streams. (Fresh water underground is called groundwater and oceans are not freshwater). Fresh water sources are generally characterized by having low concentrations of dissolved salts (below 1,000 mg/l) and other total dissolved solids.CDP Water Reporting GuidanceLink
FreshwaterThe most common freshwater use is potable municipal or city water (drinking water).  Other sources can be from ground water wells, surface waters (lakes, rivers, and streams), rain water, and even condensate when collected from steam which is supplied to the business from an external source.Higg Index 
Freshwater FootprintFreshwater Footprint is defined as the total volume of all freshwater used to produce goods and services within a defined time period.  This includes freshwater use in canteens, dormitories, landscape irrigation, vehicle washing, etc. – all freshwater use.  The number represents the environmental impact as it pertains to freshwater use.  A sustainable business should strive to minimize freshwater footprint.  Many ways can be used to reduce freshwater use, including: fixing leaks, manufacturing process efficiency improvements, technology upgrades, reuse, and recyclingHigg Index 
FugitiveFugitive emissions are defined as those emissions which could not reasonably pass through a stack, chimney, vent, or other functionally-equivalent openingUS EPALink
Global Harmonization System (GHS)GHS stands for the Globally Harmonized System of Classification and Labelling of Chemicals. GHS defines and classifies the hazards of chemical products and communicates health and safety information on labels and safety data sheets). The goal is that the same set of rules for classifying hazards, and the same format and content for labels and safety data sheets (SDS) will be adopted and used around the world. An international team of hazard communication experts developed GHS.CCOHSLink
Greenhouse gases emissions (GHG)

Gases that trap heat in the atmosphere are called greenhouse gases. The primary human activity affecting the amount and rate of climate change is greenhouse gas emissions from the burning of fossil fuels. The most common GHG, regulated under the Kyoto Protocol and are usually accounted in GHG inventories, are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and Nitrogen trifluoride (NF3).

A site’s GHG emissions, sometimes called ‘carbon footprint,’ refer to the amount of GHG emitted to the atmosphere as a result of the site’s activities, whether from energy use, refrigerant use and wastewater treatment or other. The scope of measuring and tracking of a site’s GHG emissions is defined by different international accounting standards like the ISO14064, GHG Protocol – A Corporate and Accounting Standard (Revised Edition), etc. Local GHG accounting requirements and standards may be available.

Adapted from US EPA and GHG Protocol 
GroundwaterWater in soil beneath the soil surface, usually under conditions where the pressure in the water is greater than the atmospheric pressure, and the soil voids are substantially filled with the water. Non-renewable groundwater is generally located at deeper depths and cannot be replenished easily or is replenished over very long periods of time. They are sometimes referred to as “fossil” groundwater sources.CDP Water Reporting GuidanceLink
Hazardous wasteHazardous waste is waste that could cause harm to public health and/or the environment because of its chemical, physical, or biological characteristics (e.g., it is flammable, explosive, toxic, radioactive, or infectious). The U.S. Environmental Protection Agency defines hazardous waste as “waste that is dangerous or potentially harmful to our health or the environment. Hazardous wastes can be liquids, solids, or gases, or sludge.US EPA 
Higg FEM TrainerAn Individual qualified to provide Higg Index FEM Training.Higg FEM Training ProgramLink
Incinerated with energy recoveryMaterials that are collected and intentionally allocated to incineration, gasification, anaerobic digestion, or other technology that recovers the inherent useful energy of the material. Methods that prevent environmental impacts and maximize resource utilization are required.Higg Index 
Insulation MaterialsSubstance used to reduce or prevent the transmission of heat, sound or electricity. Insulation materials can be natural (e.g. duck/goose down, or wool) or synthetic (e.g. polyester insulation).  
IncinerationMaterials that are collected and managed through an incineration process that meets international standards.Higg Index 
LandfillMaterials that are collected and managed through a landfilling process that meets international standards.Higg Index 
LeachateLeachate is the liquid (e.g.: rain) that drains or ‘leaches’ (e.g. water contained in food waste) from waste when water percolates through any waste. It varies widely in composition regarding the age of the waste and the type of waste. It usually contains both dissolved and suspended material.Higg Index 
Manufacturing Restricted Substance Lists (MRSLs)The ZDHC MRSL is a list of chemical substances subject to a usage ban (see Usage Ban, page 2). The MRSL applies to chemicals used in facilities that process materials and trim parts for use in apparel and footwear.  Chemicals in the ZDHC MRSL include solvents, cleaners, adhesives, paints, inks, detergents, dyes, colorants, auxiliaries, coatings and finishing agents used during raw material production, wet-processing, maintenance, wastewater treatment, sanitation and pest control.ZDHCLink
Material waste

These wastes may include scrap generated during the production or leftover / unused.

Some example of material waste in Apparel, Textiles, and Footwear industry (not exhaustive) are:

• Leather (synthetic or natural)

• Glass

• Fabric (Cotton or Nylon or blended)

• Polyurethane Foams (laminated or unlaminated)

• Lining materials

• Rubber


• Lining materials

• Mixed material waste.

Higg Index 
Municipal waterWater provided by a municipality or other public provider.CDP Water Reporting GuidanceLink
Non-Hazardous wastesDiscarded materials from the consumption of goods and services and the manufacture of goods (e.g. cloth, leather, plastic, and paper or packaging waste. Non-hazardous waste usually includes non-hazardous production waste and domestic waste. Non-hazardous waste, such as food waste or plastic waste can still pose contamination and fire risks if not properly managed.Higg Index 
Normalized dataNormalized data includes a comparison of totals or usage data against a predefined variable (or set of variables), e.g. kWh of electricity used per employee on-site, kg of hazardous waste per unit of production etc. An organization can decide whether absolute or normalized data are going to be the most appropriate and representative data to collate/report. Within each of the performance areas discussed in this document there are examples of variables against which data can be normalizedGSCP 
Normalized reductionsReduction in actual utility consumption (e.g. average kWh of electricity used, or cubic meter of water used per employee on-site within a calendar year)/pollution generated (e.g. average kg of hazardous waste per unit of production within a calendar year) that has been normalized to a business metric (e.g. units or mass of production, unit revenue, unit gross sales, unit turnover, full-time employee equivalent, square foot) when compared to normalized utility/pollution generated in a base year. To calculate a normalized value, measure utility/pollution generated in a given time period and divide by the chosen business metric. For example, a normalized waste generation can be calculated as follows: 10,000 kg waste ÷ 5,000 garments = 2kg waste/garment.  
Off-site wastewater treatmentOff-site wastewater treatment is a third-party enterprise or organization who provides wastewater treatment service for more than two pollutant discharging entities by collecting their wastewater, and the wastewater discharged directly to environment should meet with the relevant limits. The off-site treatment can be public wastewater treatment facility, regional wastewater treatment facility (i.e. industrial park, industry area etc.)Higg Index 
On-site wastewater treatmentOn-site wastewater treatment is the wastewater treatment plant used and managed by the factory only. After treated by the on-site treatment, the wastewater can meet with relevant limits and be directly discharged into the environment, or into an Off-site 3rd party treatment plant (known as partial onsite treatment).Higg Index 
Open burningOpen burning is outdoor burning of wastes such as lumber, scrapped cars, textiles, sawdust and so forth.OECDLink
PermitPermit is defined as all documents required to comply and submit to government, including but not limited to governmental permits, authorizations, licenses, registrations, certificates, annual government reports and registration of specific chemicals use.Higg Index 
Personal protective equipmentPersonal protective equipment, commonly referred to as “PPE”, is equipment worn to minimize exposure to hazards that cause serious workplace injuries and illnesses. These injuries and illnesses may result from contact with chemical, radiological, physical, electrical, mechanical, or other workplace hazards. Personal protective equipment may include items such as gloves, safety glasses and shoes, ear plugs or muffs, hard hats, respirators, or coveralls, vests and full body suits.US Department of laborLink
Preventative maintenancePreventative maintenance (or preventive maintenance) is maintenance that is regularly performed on a piece of equipment to lessen the likelihood of it failing. Preventative maintenance is performed while the equipment is still working, so that it does not break down unexpectedly.FiixLink
Process waterWater consumed for industrial purposes, such as laundry, finishing or feed-in water for boiler.Higg Index 
Produced/process waterWater which, during extraction or processing, comes into direct contact with or results from the production or use of any raw material (e.g. crude oil or a by-product from sugar cane crushing), intermediate product, finished product, by-product, or waste product. Note this also includes reused / recycled water.CDP Water Reporting GuidanceLink
RainwaterIf a company is managing rainwater, either to harvest and use, or to prevent flooding for example, they should try to estimate and disclose it as withdrawal from the hydrological system. This helps companies better understand their water dependency and risks.CDP Water Reporting GuidanceLink

Requires the waste to be re-processed so as to obtain a product, material or substance whether for the original or other purposes. It does not include energy recovery and the reprocessing into materials that are to be used as fuels or for backfilling operation. For example:

  • Plastic recycling is the process of recovering scrap or waste plastic and reprocessing the material into useful products, sometimes completely different in form from their original state. For instance, this could mean melting down soft drink bottles and then casting them as plastic chairs and tables.
  • Plastic used for playground surfaces or traffic cones
  • Padding/stuffing used for furniture, mattresses, blankets, toys
Higg Index 
Recycled Water

Recycled Process Water: treated effluent used again in main process

Reused Water: treated effluent used in other areas except recycled water such as toilets or landscaping

Recycled water is the reuse of wastewater that has been treated to remove solids and certain impurities to meet water quality standards associated with the designated application.

CDP Water Reporting GuidanceLink
Renewable energy

This relates to energy generated by a renewable source (i.e. source which is not depleted or used up as it is naturally replenished. Renewable sources can either be managed so that they last forever, or so that their supply is not significantly impacted.

Unlike fossil fuels, most renewable energy sources do not release carbon dioxide and other air pollutants as by-products into the atmosphere. As the amount of fossil fuel resources on Earth decreases, it is becoming increasingly important to find and utilize renewable energy sources. Examples include: solar, biofuels, wind, hydroelectric, geothermal, tidal and wave.

Restricted Substance Lists (RSLs)A list, compiled by a business, trade group or other organization, of chemicals (aka chemical substances) to be actively managed and informed on. An RSL may contain chemicals for controlled use, targeted for elimination/substitution, and those that may be totally banned or may be regulated. (e.g., American Apparel and Footwear Association (AAFA) RSL)OIA – Chemicals Management Framework Glossary 

Means checking, cleaning or repairing recovery operations, by which products or components of products that have become waste are prepared so that they can be re-used without any other preprocessing whether for the original or other purposes. For example:

  • Chemical supplier can reuse the chemical container for filling them up with the same chemical
  • Fabric leftover can be reused in another factory
  • Rechargeable batteries can be reused many times
Higg Index 
Rubber materialA tough, flexible, highly resilient, waterproof material. Natural rubber is produced using an organic compound (isoprene) usually harvested in the form of latex from rubber trees. A synthetic rubber is any artificial elastomer (polymer with elastic properties).  
Safety Data Sheets (SDS)SDS (also called material safety data sheet (MSDS) or production safety data sheet (PSDS)) is an important component of product stewardship and occupational safety and health. It is intended to provide workers and emergency personnel with procedures for handling or working with a substance in a safe manner and should include information such as physical data (melting point, boiling point, flash point, etc.), toxicity, health effects, first aid, reactivity, storage, disposal, protective equipment, and spill-handling procedures.Higg Index 
Scope 1 emissionsDirect GHG emissions occur from sources that are owned or controlled by the company, for example, emissions from combustion in owned or controlled boilers, furnaces, vehicles, etc.; emissions from chemical production in owned or controlled process equipment.GHG protocolLink
Scope 2 emissionsScope 2 accounts for GHG emissions from the generation of purchased electricity consumed by the company. Purchased electricity is defined as electricity that is purchased or otherwise brought into the organizational boundary of the company. Scope 2 emissions physically occur at the facility where electricity is generated.GHG protocolLink
StakeholdersStakeholders are defined broadly as those groups or individuals: (a) that can reasonably be expected to be significantly affected by the organization’s activities, products, and/or services; or (b) whose actions can reasonably be expected to affect the ability of the organization to successfully implement its strategies and achieve its objectives.GRI G3 2001 
Standard Allowed Minute (SAM) or Standard Minute Value (SMV)

Standard Minute Value, or SMV, is the time value arrived at for a task based on the average rate of output which qualified workers will naturally achieve without over exertion provided that they know and adhere to the specified method and provided that they are motivated to apply themselves to their work. (ILO)

Note that SMV is often used interchangeably with Standard Allowed Minute, or SAM.

International Labour OrganizationIntroduction to Work Study, 4th ed.
Synthetic leather materialsA synthetic (man-made and typically petroleum-based) material used as a substitute for leather.  

A formal target here refers to a quantified performance requirement of the site’s annual utility use of a particular utility source. A formal target must:

1) include a definite start date (i.e., “baseline”) of target, the measurement unit, and the baseline consumption (i.e. m3/year at 2010 baseline)

2) include an end date of the target, meaning the intended completion of the required reductions; and

3) include an exact reduction quantity, expressed as a number (e.g. reduce by 1 million m3) or a percentage (e.g. reduce by 5%).

4) be relevant to reducing the site’s utility use (e.g. focuses on the most significant utility uses at the site)

Higg Index 
Total suspended solids (TSS)A measure of the suspended solids in wastewater, effluent, or water bodies, determined by tests for “total suspended non-filterable solids”.OECDLink
UnitsUnits refer to common consistent units.  Examples: If dyeing or using wet processes proper units would be volume/mass. For finished goods, proper units are volume/piece.Higg Index 
UpcyclingUpcycling is the process of transforming by-products, waste materials, useless and/or unwanted products into new materials or products of better quality or for better environmental valueHigg Index 
Verifier – Chemical Specialist

An individual qualified to verify Higg Index FEM scores for all facilities. Must be used to verify facilities where Level 1, 2 and Level 3 chemical management sections apply.


Cascale Verification Program 
Verification Code of ConductThe norms and behaviors expected of an Cascale approved verifier during a verification.Cascale Verification Program 
Verifier Criteria

The set of criteria for which individuals and the companies they work for are vetted against to determine provisional acceptance or denial as an Cascale approved verifier.


Cascale Verification Program 
Verifier – Generalist

An individual qualified to verify Higg Index FEM scores for all facilities that are applicable to only Level 1 chemical management section questions. Except when facilities are classified as not using chemicals in production.


Cascale Verification Program 
Verification – OffsiteWhen an Cascale approved verifier conducts a verification remotely by, web conference, photo and/or file submitted via e-mails or other means which do not require the verifier to enter onto the manufacturer premises.Cascale Verification Program 
Verification – OnsiteWhen an Cascale approved verifier conducts a verification by entering onto the manufacturer premises and completes the verification in person.Cascale Verification Program 
Verification Person DayThe number of verifiers and number of days it takes to complete the verification process.  For example, 2 person days can be 2 verifiers completing a verification on one day or 1 verifier completing a verification in two days. Both of these scenarios would each equal a total of 2 person days.Cascale Verification Program 
Verification Performance Improvement Plan (PIP)The verification result outcome which is a template manufacturers use to help track their continuous improvement.Cascale Verification Program 
Verification ProgramEstablishes the guidelines and protocol for approving verifiers and conducting module verifications.Cascale Verification Program 
Verification Program Manager (VPM)

An external party to help with scale and expertise to manage the day to day operations of the program. Cascale and members will be involved in overseeing the overall health of the program, providing strategic guidance, and building enhancements.


Cascale Verification Program 
Verifier Protocol

The step-by-step guide and set of requirements for verifiers conducting either off-site or on-site verification.


Cascale Verification ProgramLink
Verifier Training

Required training for Verifiers to become eligible to conduct Verification.


Cascale Verification Program 
Waste inventory

A waste inventory records information of all waste stream generated on-site, it could include information on:

  • nature of the waste (hazardous/non‐hazardous);
  • its source (e.g. process, area);
  • the physical form of the waste (solid, liquid etc.);
  • formal classification code (if applicable);
  • specific handling/ storage arrangements;
  • the quantity of waste disposed of/treated;
  • the disposal/treatment method (biological, chemical, physical),
  • including any on‐site treatment;
  • details of waste contractors used; and
  • disposal/treatment route (recycled, landfill, incineration)
Higg Index & GSCP 
Waste ManifestEPA’s hazardous waste manifest system is designed to track hazardous waste from the time it leaves the generator facility where it was produced, until it reaches the off-site waste management facility that will store, treat or dispose of the hazardous waste.USEPALink
Waste minimizationThe policy and process to have the waste minimization means to reduce the production of waste at society and individual level. The wider part of the aim, which is remarked as waste reduction, is often understood as waste hierarchy.Waste Management ResourcesLink
WastewaterCeres Aqua gauge defines wastewater as “Water that is of no further immediate value to the purpose for which it was used or in the pursuit of which it was produced because of its quality, quantity or time of occurrence.” Cooling water is not considered to be wastewater. Wastewater is also defined as water of a quality that no longer serves a useful purpose for the business and is normally discharged under a permit from the property.CDP Water Reporting GuidanceLink
Wastewater quality

Wastewater quality may be measured using many factors, such as suspended solids, reduced biological oxygen demand (BOD) or chemical oxygen demand (COD), metals content, oil/grease content, temperature, pH, etc.

Wastewater quality can be improved through reducing strength/concentration of contamination at the source of generation and should be considered top priority, before targeting to reduce wastewater volume.

Wastewater treatment volume and quality are tightly linked.  It is important to not focus solely on one without understanding how it affects the others.  For instance, if you decrease your wastewater discharge volume, you may inadvertently create wastewater quality that is untreatable (on-site or off-site) and have a net-negative impact. Wastewater generation should be compared between fixed periods so that unusual patterns in generation can be identified.

Wastewater quality target

A formal target here refers to a quantified performance requirement of the site’s wastewater discharge quality. A formal target must:

1) include a definite start date (i.e., “baseline”) of target and the performance level (at least COD, BOD, TSS, temperature, and pH) at baseline date;

2) include an end date of the target, meaning the intended completion of the required reductions/ improvements; and

3) include an exact reduction quantity or extent, expressed in an absolute number or a percentage.

4) be relevant to improving the site’s wastewater discharge quality.

Formal targets in this instance may be absolute or normalized.

Absolute = total volume of wastewater discharged regardless of variables (facility size, process volumes, production hours, raw material usage, etc.)

Normalized = volume of wastewater discharged relative to some relevant variable (e.g., volume of wastewater discharged per unit of production)

Higg Index & GSCP 
Water BalanceA basic water balance is an equation used to describe flow of water into and out of the facility.  The total metered influents would equal to the total of all effluents and water losses.Higg Index 
Water recyclingWater recycling is a reliable water supply which significantly lowers a facility’s water footprint.  Advances in wastewater treatment technology and recycling ability enable business growth while minimizing environmental impact.  As freshwater supplies around the world experience increased stress due to demand, recycling will play a greater role in overall water supply strategies.Higg Index 
Zero Liquid DischargeZero-liquid discharge (ZLD) is a treatment process that design for no water leaves a facility in liquid form. At a facility with on-site ZLD treatment system, almost all wastewater is treated and recovered such that the only water discharged from the facility exists by evaporation or as moisture in the sludge from treatment plant operations.  A facility is not considered to have a ZLD treatment system if there is a liquid discharge.ZDHC Wastewater GuidelineLink