SWMP TAC Sanitary Wastewater Master Plan Technical Advisory Committee
TN Total nitrogen
TON Total organic nitrogen
TP Total phosphorus
TSS Total Suspended Solids
TTHM Total trihalomethane
UIC Underground Injection Control
URM Urban Residential Mobile Home
USACE U.S. Army Corps of Engineers
USDW Underground source of drinking water
USFWS U.S. Fish and Wildlife Service
USGS U.S. Geological Survey
WQPP Water Quality Protection Program
WWTP Wastewater Treatment Plants
DefinitionsAbandonment costs – These include the expenses associated with removal and disposal of an existing wastewater treatment system.
Adsorption – Adhesion of molecules of gases or of ions or molecules to the surfaces of solid bodies with which they are in contact.
Advanced Wastewater Treatment (AWT) – Also known as tertiary treatment, AWT follows Secondary Treatment. Removal of soluble nitrogen and phosphorus compounds is a common application of AWT. AWT may involve chemical addition, filtration, or activated carbon processes. As referred to in the MCSWMP, effluent treated to AWT standards meets 5 mg/L BOD, 5 mg/L TSS, 3 mg/L TN, and 1 mg/L TP.
Anthropogenic – Relating to humans and their impact on the natural environment
Belt Filter Press Dewatering – A process used to remove water from sludge thereby producing dewatered biosolids that contain equal to or greater than 20% dry solids.
Benthic Algae – Algae relating to the bottom of a water body.
Best Available Technology (BAT) – The level to which wastewater treatment systems are designed. As referred to in the MCSWMP effluent treated to BAT standards that 10 mg/L BOD, 10 mg/L TSS, 10 mg/L TN, and 1 mg/L TP.
Best Management Practices (BMP) – A set of minimum practices developed and implemented to improve the physical, chemical, and biological integrity of the nation’s waters. Examples include installation of silt fencing at a construction site to prevent eroded soils from entering a nearby waterway.
Biochemical Oxygen Demand/Biological Oxygen Demand (BOD) – The oxygen that is needed and used by aerobic organisms living in water that is rich in organic material (such as waters polluted by sewage).
Boulder Zone – A very permeable, cavernous zone in the lower Floridian Aquifer System that is about 2800 to 3300 feet below ground surface.
Calcareous – Containing calcium carbonate. As applied to rock, the predominant percentage of the rock is calcium carbonate.
Cesspool/Cesspit – An unregulated and unpermitted effluent disposal method that consists of an excavated area (100 to 1000 cubic feet, 4 to 8 feet deep) into the ground surface. The area is covered with a slab of concrete, and untreated sewage is then deposited into the pit. Liquid wastes are discharged through the porous limestone formations and ultimately to the nearshore areas. Solid wastes are retained in the pit, which is often abandoned after it becomes full.
Class B Lime Stabilization – The process used to reduce harmful bacteria and odors in sludge or biosolids. Lime is added to untreated sludge in sufficient quantity to raise the pH to 12 or higher. The high pH creates an environment that is not conducive to the survival of microorganisms. Class B Lime Stabilization refers to the EPA classification for the safe treatment, beneficial use, and disposal of biosolids that contain pathogen concentrations levels low enough for some beneficial uses, such as land application with restrictions.
Class I Injection Well – The first of five well classifications developed by the U.S. Environmental Protection Agency under their underground disposal control program to categorize the injection of various types of liquid wastes. Class I wells are typically used by hazardous waste generators and operators, as well as industrial and municipal disposal systems, to inject fluids into a geologic formation that is beneath the lower-most formation containing an underground source of drinking water within ¼ mile of the well bore. A Class I Well must meet siting, construction, operation, and maintenance criteria specific to this well class, as established by the U.S. Environmental Protection Agency and the Florida State regulating agency.
Class V Injection Well – Similar to a Class I Injection Well, the U.S. Environmental Protection Agency established this well category for a broad range of specialty applications to dispose liquid wastes, which are not categorized under the other four injection well classes. For example, a Class V well could be used to drain stormwater runoff into an aquifer.
Cluster System (of OWNRS) – An OWNRS that serves multiple homes. Clusters can be composed of small groups (such as 2 homes), which share one treatment system, or of large groups (50 homes), which use low-pressure sewers to connect the cluster to a centralized OWNRS.
Effluent – The waste stream from a wastewater treatment system collection unit.
Enteric – Relating to the intestines. Over 100 different human enteric pathogens, including viruses, parasites, and bacteria may be found in municipal wastewater and surface runoff.
Enterococci – A bacterium whose presence indicates Fecal Coliform.
Environmental Impact Statement (EIS) – A public document prepared pursuant to NEPA containing a detailed analysis and evaluation of all the impacts of a proposed major federal action and all its reasonable alternatives that has the potential to significantly affect the quality of the human environment. This is a more rigorous analysis than an Environmental Assessment and provides for formal public involvement.
Epiphyte – A plant growing on another plant but getting little nutrition from its host.
Equivalent Dwelling Unit (EDU) – A household of 2.3 persons generating about 168 gallons of effluent per day.
Eutrophication – The process by which a body of water becomes nutrient-rich and oxygen-deficient.
Executive Order (EO) – A Presidential mandate that directs a federal agency to consider certain issues as an agency plans their actions. For example, former President Jimmy Carter directed all agencies to “minimize the destruction and loss or degradation of wetlands” under EO 11990, “Protection of Wetlands.”
Fecal Coliform – A bacterium used as an indicator of total sewage biological contamination.
Florida Statutory Treatment Standards – Quality standards for discharged wastewater effluent as promulgated in F.A.C. 99-395. Treated effluent generated by sewage facilities with design capacities greater than 100,000 gpd must meet 5 mg/L TP. Sewage facilities with design capacities less than 100,000 gpd must meet 10 mg/L BOD, 10 mg/L TSS, 10 mg/L TN, and 1 mg/L TP. On-site sewage treatment and disposal systems must meet 10 mg/L BOD, 10 mg/L TSS, 10 mg/L TN, and 1 mg/L TP.
Hydraulic Communication – Water movement from one area to another (such as from the Boulder Zone to the ocean).
Hydraulic Conductivity – An aquifer’s water transmission rate; similar to transmissivity.
Hydraulic Head – The driving force influencing groundwater movement, water’s total energy at a given location.
Injection Well (shallow and deep) – An underground well designed to pump treated effluent (or other materials) into shallow (e.g., 90 feet) or deep (e.g., 2,100 feet) geologic locations. Injection wells are designed to account for physical and chemical characteristics of the injection matrix, and require monitoring to ensure mechanical integrity of the well.
Lateral costs – These include the expenses associated with installing wastewater piping on the service recipient’s property for connection to the conveyance piping in the street for a new wastewater system.
Lithologic – A rock’s descriptive characteristics, including color, structure, mineral composition, and grain size.
Median Family Income (MFI) – as defined by the U.S. Census Bureau, refers to the income of a family where a family is defined as two or more people (one of whom is the householder) related by birth, marriage, or adoption residing in the same housing unit.
Median Household Income (MHI) – as defined by the U.S. Census Bureau, refers to the income of a household where a household is defined as all people who occupy a housing unit regardless of relationship. A household may consist of a person living alone or multiple unrelated individuals or families living together.
Microkarst – Karst features on the scale of millimeters. Karst is a type of landform developed over limestone, dolomite, or gypsum through solution of the rock, typified by closed depressions, caves, and underground drainages.
National Environmental Policy Act (NEPA) – A congressional act established in 1969 that directs all federal agencies to consider the environmental effects of their programs, projects, and funding decisions. NEPA considers the effects on all resources of natural and built environments and includes compliance requirements with all other applicable federal laws, such as the Endangered Species Act and the Environmental Justice Executive Order.
Norwalk Virus - Norwalk viruses (and related caliciviruses) are important causes of sporadic and epidemic gastrointestinal disease in the United States, and have typically been associated with eating contaminated shellfish. Water and ice are other sources of infection. Symptoms of Norwalk virus infection include nausea, vomiting, diarrhea, headache, low-grade fever, and abdominal cramps. Persons with this infection usually recover within 2-3 days without serious or long-term health effects.
Oligotrophic – A body of water that is nutrient-poor.
On-Site Wastewater Nutrient Reduction System (OWNRS) – An on-site wastewater treatment system that meets a minimum level of BAT treatment, or 10 mg/L BOD, 10 mg/L TSS, 10 mg/L TN, and 1 mg/L TP.
On-Site Wastewater Treatment System (OWTS) – Any of several wastewater treatment types that are located on the property they serve. Examples include septic systems, cesspools, aerobic treatment units (ATU), and On-Site Wastewater Nutrient Reduction Systems (OWNRS).
Operation and maintenance (O&M) costs – These include the monthly or annual costs incurred by service recipients for long-term operation and maintenance of the wastewater management system.
Permeability – The capacity of porous material to transmit water or other fluid. In bedded sediments, horizontal permeability is measured parallel to the bedding direction, and vertical permeability is measured transverse to the bedding.
Phytoplankton - Plant plankton, which float or weakly swim, are often microscopic (e.g., many algae species), and are the primary food source in most aquatic and marine ecosystems.
Primary Treatment – The first level of wastewater treatment that removes solids, greases, oils and other floatable solids from the waste stream, partially clarifying the effluent. Suspended solids, dissolved organic materials, and other pollutants are not removed from the effluent.
Programmatic Environmental Assessment (PEA) – A concise public document prepared pursuant to NEPA. It contains sufficient analysis to determine the likely significance of a group of similar proposed actions (projects) and alternatives’ impacts, to aid decision making as to whether or not to prepare an EIS. A project- and site-specific effects evaluation document supplements the PEA, generically called a Supplemental Environmental Review (SER), (described below).
Secondary Treatment – Used in concert with Primary Treatment. This second level of treatment removes dissolved organic materials and more suspended solids, however nutrients such as nitrogen and phosphorus remain in the effluent.
Septic Tank – An OWTS using a tank and drainfield to capture waste, separate solids from liquids, and drain liquid to adjacent soils.
Significantly – In the NEPA context, this term is used to describe both the context and intensity (severity) of impacts. For a detailed description of this term, see Section 1508.27 of the President’s Council on Environmental Quality’s regulations implementing NEPA.
Slurry – Mixture of coarsely ground solids and liquid.
Specific Gravity – Ratio of a given mass to the mass of an equal volume of water at a specified temperature.
Subsurface Drip Irrigation (SDI) – A form of clarified effluent disposal with discharge into soils via subsurface piping.
Supplemental Environmental Assessment (SEA) – A secondary NEPA public document that references relevant data presented in the PEA and presents site- and project- specific details and evaluation of effects.
Supplemental Environmental Review (SER) – A generic phrase used herein for referencing the site- and project-specific NEPA document that would be prepared following issuance of a final PEA. This document would be either an SEA or EIS depending on the significance of the specific project impacts.
System capital costs – These include expenses associated with planning, designing, engineering, purchasing, building, and installing a wastewater treatment system, and its wastewater conveyance piping in public right-of-ways and selected effluent disposal method (e.g., injection wells, SDI, reuse).
Total Nitrogen/Nitrogen (TN/N) – Nitrogen is a common element found in nature and in wastewater. Nitrogen is an essential nutrient for plants, but contributes to water body eutrophication when more abundant. “Total nitrogen” describes nitrogen in four oxidation states: organic nitrogen, ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen. Removal or reduction of TN from wastewater effluent involves nitrification (where organic N and ammonia N are converted to nitrite N, which easily converts to nitrate N) and denitrification (where nitrate N is converted to nitrogen gas).
Total Phosphorus/Phosphorus (TP/P) – Phosphorus is a natural element, however most phosphorus enters waterways via human activities (i.e., untreated wastewater or fertilizer runoff). Similar to nitrogen, phosphorus is an essential nutrient for plants, but eutrophication occurs when phosphorus is more abundant. “Total phosphorus” is in organic and inorganic forms and can occur in solution, particles, or micro-organisms (such as polyphosphates, which account for 70% of wastewater phosphorus). TP removal or reduction from wastewater effluent typically involves biological treatment (to convert P to the orthophosphate forms), which are then removed via chemical processes.
Total Suspended Solids (TSS) – TSS are solids in water, such as silt, decaying plant and animal matter, and sewage, that can be trapped by a filter. High concentrations of suspended solids can cause many problems for water body health and aquatic life. For example, high TSS can block light from reaching submerged vegetation.
Transmissivity – An aquifer’s ability to transmit water, proportional to the aquifer’s saturated thickness; similar to Hydraulic Conductivity.
Turbidity – A measure of the water clearness as a function of suspended sediment.
Vector Attraction Reduction – Decreasing the characteristic of sewage sludge that attracts rodents, flies, mosquitoes or other organisms that transmit infectious agents.
Wastewater Treatment Plant (WWTP) – An effluent collection, treatment, and disposal system that collects waste from homes and businesses, and transports collected waste through a series of sewers to a centralized treatment plant. Physical, chemical, and biological processes clarify the effluent at the WWTP so that the treated water can be safely released into the environment via water reuse, deep or shallow well injection, or other permitted methods.
Hot Spot Locations
Water Quality Improvement AnalysisComparison of Nutrient Contributors from Islamorada Service Area to Groundwater and Marine Waters under Present Conditions versus Wastewater Systems that Meet AWT Standards for Effluent Disposal (5 mg/L BOD, 5 mg/L TSS, 3 mg/L TN, 1 mg/L TP)
Sources of Information:
Average daily flow (gpd): Islamorada (2001a) Design/Build/Operate Wastewater Management System(s), Islamorada, Village of Islands.
Raw sewage nutrient concentration: Ayres Associates (1998).
Nutrient removal by septic systems (TN 4%, TP 15%) Kruczynski (1999, Table 7).
Removal of TP from groundwater by chemical reaction with aquifer limestone Kruczynski (1999, p. 22)
Removal efficiency of AWT for TN, TP Islamorada (2001a, p. 18), and disposal of AWT effluent to Class V shallow wells Islamorada (2001a, p. 26).
Currently all sewage disposal is by onsite septic systems; no cesspit/cesspool systems; and inflows total – AWT system average daily flow.
TP is not removed from groundwater by reaction with aquifer limestones. This is a conservative assumption.
Raw sewage nutrient concentrations are the same as Big Pine field experiments (Ayres Associates, 1998, p. 5-1).