HomeMy Public PortalAboutH Program Summary GlossaryGLOSSARY
BIORETENTION A concave landscape feature which stores, filters, and infiltrates
stormwater runoff.
BIOSTABILIZATION A method of repairing eroding streams by utilizing the structural properties of live plants to rebuild eroded streambanks and incised
channels.
BIOSWALE A sloped open drainage channel with landscape elements designed to
store, filter, and infiltrate stormwater runoff.
CD The Federal Consent Decree, entered on April 27, 2012 and all appendices and all modifications or amendments thereto, between
MSD, United States of America, and the Missouri Coalition for the
Environment Foundation designed to eliminate or reduce overflows from the Combined and Separate Sewer Systems in order to improve
water quality and protect human health and the environment.
CIPP Cured in Place Pipe, a construction method to rehabilitate a sewer pipe by lining it with a new pipe. This work does not require excavating the
pipe and replacing it in total.
CIRP Capital Improvement and Replacement Program, the ongoing system improvement efforts by MSD.
CMOM Capacity, Management, Operations, and Maintenance program.
COE United States Army Corps of Engineers.
COMBINED SEWER The portion of MSD's sewer system designed to convey municipal
sewage (i.e. domestic, commercial and industrial wastewaters) and
stormwater runoff through a single-pipe system to a wastewater treatment facility and/or to a CSO outfall.
CONSENT DECREE See “CD”.
CSO Combined Sewer Overflow, any discharge from the combined sewer system at a point prior to the headworks of a wastewater treatment facility.
FORCE MAIN A pressurized sewer pipe that can carry wastewater. Sewer force mains
are necessary when topography, or other system characteristics, do not
allow wastewater to move through the line by the influence of gravity alone. Force mains are the pipes that convey wastewater under pressure
through the work of pumps located in pump stations or lift stations.
GI Green Infrastructure, environmentally friendly and sustainable
stormwater management practices that reduce runoff by using
infiltration, such as bioretention and bioswales.
GRADE CONTROL STRUCTURE A structure constructed in a creek or stream to control erosion. The structure allows water to pass to a lower elevation while directing the
energy and velocity of the water in a manner that minimizes erosion
that would otherwise change the shape of the stream.
GLOSSARY
I/I Inflow and Infiltration; inflow refers to direct connections of rainwater
sources to the sanitary sewer system; infiltration refers to groundwater sources of flows into sewer pipes. Inflow sources can include roof
downspouts, yard and area drains, foundation drains, manhole covers,
cross connections from storm sewers, or inlets. Infiltration sources can include defective building laterals, sewer pipes, pipe joints,
connections, or manhole walls.
INFILTRATION Infiltration refers to groundwater sources of flows into sewer pipes. Infiltration sources can include defective building laterals, sewer pipes,
pipe joints, connections, or manhole walls.
INFLOW Inflow refers to direct connections of rainwater sources to the sanitary
sewer system. Inflow sources can include roof downspouts, yard and area drains, foundation drains, manhole covers, cross connections from
storm sewers, or inlets.
LATERAL A sewer connecting a building with the publicly owned sanitary sewer
main.
LIFT STATION Lift stations are used for pumping wastewater or stormwater from a point of lower elevation to a point of higher elevation. Lift stations utilize pumps to lift the wastewater from the lower elevation to the
higher elevation. Wastewater then flows by gravity to the next location in the system.
LMRDP Lower and Middle River Des Peres, generally the river from University City south to the Mississippi River.
LTCP Long Term Control Plan, a long duration plan to manage/improve the combined sewer system and abate combined sewer overflows, through
the identification of a capital improvement plan tailored to receiving stream water quality and the community's financial capability.
MAIN A smaller public sewer collecting flows from buildings via lateral connections.
MGD Million Gallons per Day, a measure of flow over time. 1 MGD is
equivalent to 700 gallons per minute of flow.
MSD Metropolitan St. Louis Sewer District, district formed in 1954 via vote of the people, with responsibility for wastewater and stormwater services in St. Louis City and most of St. Louis County.
OMCI Operation Maintenance Construction Improvement district, funds
generated by tax payments in certain districts can be used for capital
improvements in those districts. Funds can be used for capital projects or maintenance.
OUTFALL The point of discharge to the environment from a constructed SSO or CSO.
PRIVATE I/I REDUCTION Reduction of inflow and infiltration sources on private property, from
private sources, such as downspout and driveway drain connections to the sanitary sewer system (inflow) or deteriorated service laterals or
broken connections (infiltration).
PUBLIC I/I REDUCTION Reduction of public inflow and infiltration sources such as cracked and
broken sewer pipes or deteriorated manholes.
GLOSSARY
PUMP STATION Pump stations are facilities which include pumps and ancillary
equipment, for pumping fluids from one place to another. A pump is a mechanical device that converts mechanical energy to pressure, in order
to convey wastewater or stormwater. Pumping results in pressurized
sewer pipes that are called force mains.
RAIN GARDEN A landscaped shallow swale or depression that temporarily holds water
and reduces stormwater runoff as the water infiltrates into the soil. The water is absorbed by plants and is filtered as it percolates through the
soil.
RAINSCAPING Any combination of plantings, water features, catch basins, permeable
pavement and other activities that manage stormwater as close as possible to where it falls, rather than moving it someplace else.
RDP River Des Peres, a river in the central and south portions of the metropolitan area, which was enlarged in the early 1900s to provide
conveyance to the Mississippi River of stormwater runoff in order to reduce surface flooding.
RFP Request for Proposals.
RFQ Request for Qualifications.
SANITARY SEWER SYSTEM The portion of the sewer system designed to convey only sewage, and not stormwater, from residences, commercial buildings, industrial
plants and institutions for treatment at a wastewater treatment facility
SKME Sverdrup Kwame Metcalf Eddy - a planning team that identified system needs in the early 2000s.
SSO Sanitary Sewer Overflow, any overflow, spill, diversion, or release of wastewater from or caused by MSD's sanitary sewer system. This CD
term shall include: (i) discharges to surface waters of the State or United States from MSD's sanitary sewer system and (ii) any release of
wastewater from MSD's sanitary sewer system to public or private
property that does not reach waters of the United States or the State.
SSO MP Sanitary Sewer Overflow Control Master Plan, a capital improvement plan which describes the results of system evaluations and the specific
measures that will result in the Elimination of all Constructed SSOs
Outfalls, all known SSOs, and Building Backups, and/or that are necessary to ensure that there is adequate capacity in the Sanitary Sewer
System to collect, convey, and treat anticipated peak wet weather flows under current and projected future conditions as defined in Paragraphs 21(e) and (g) of the CD.
SUBTRUNK A sewer that serves a smaller or sub-watershed area, which brings flow
to a trunk sewer.
TRUNK SEWER A major sewer which serves a large area. A trunk sewer typically is centrally located within a watershed to which subtrunks and other
sewers are tributary.
USGS United States Geological Survey.
GLOSSARY
WASTEWATER Wastewater, also written as waste water, is any water that has been
adversely affected in quality by human influence. Wastewater can originate from a combination of domestic, industrial, commercial or
agricultural activities, and from sewer inflow or infiltration.
WATERSHED An area of land which drains to a specific creek, river, or other body of
water.
WATERSHED CONSULTANT A consulting firm retained for a multi-year design effort on a related suite of projects in a specific watershed.
WWTF Wastewater Treatment Facility, any facility, method or process which removes, reduces or renders less obnoxious pollutants or water
contaminants released from any source.
WWTP Wastewater Treatment Plant, a municipal facility that removes, reduces or renders less obnoxious pollutants or water contaminants from wastewater before releasing it to the environment.