303(d) List

Under Section 303(d) of the Clean Water Act, states are required to compile a list of impaired waters that fail to meet any of their applicable water quality standards or cannot support their designated or existing uses. This list, called a “303(d) list” is submitted to Congress every two years, and states are required to develop a Total Maximum Daily Load (TMDL) for each pollutant causing impairment for water bodies on the list.


Best Management Practices (BMP)

According to 40 CFR 122.2, schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to prevent or reduce the pollution of ‘waters of the United States’. BMPs also include treatment requirements, operating procedures, and practices to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage.


Contract Project

A construction project, which is designed either by HDOT personnel or by engineering consultant firms, and is contracted to a private contractor.


The consultant procured by HDOT in order to provide various functions in support of the requirements of the Maui District MS4 NPDES Permit.

Construction BMPs

BMPs that address a short-term storm water contamination threat during construction. They are removed at the conclusion of a construction phase or project.

Construction BMPs

BMPs to address a short-term storm water contamination threat during construction. They are removed at the conclusion of a construction phase or project.

Connection Permit

A permit issued by Highways Maui District for physical connections into the Maui District MS4.

Code of Federal Regulations (CFR)

The document that codifies all rules of the executive departments and agencies of the federal government. It is divided into fifty volumes, known as titles. Title 40 of the CFR (referenced as 40 CFR) lists all environmental regulations.

Clean Water Act

The Clean Water Act is an act passed by the U.S. Congress to control water pollution. It was formerly referred to as the Federal Water Pollution Control Act of 1972 or Federal Water Pollution Control Act Amendments of 1972 (Public Law 92-500), 33 U.S.C. 1251 et seq., as amended by Public Law 96-483, Public Law 97-117, and Public Laws 95-217, 97-117, 97-440, and 100-04.


Drainage Area

That portion of the surface area from which storm water runoff flows to a given location. With respect to a highway, this location may be either a culvert, the farthest point of a channel, or an inlet to a roadway drainage system.

Discharge Permit

A permit issued by Highways Maui District for discharges during construction into the Maui District MS4.


Any liquid, semi-solid or solid substance that is released into and from the Maui District MS4.

Detention Device

Facilities designed to collect and temporarily detain a portion of the storm water runoff for a specified period of time and to permit settlement of particulate pollutants.


Erosion Control

Stabilizing a disturbed or exposed surface area in order to prevent soil particles from being detached and causing sediment accumulation in nearby surface waters.


The wearing away of land surface, primarily by wind or water. Erosion occurs naturally as a result of weather or runoff but can be intensified by clearing, grading, or excavation of the land surface.

Encroachment Project

A construction project undertaken by a non-HDOT entity (i.e., third party) within the HDOT Highways rights-of-way and requires the issuance by HDOT of a Permit to Perform Work upon State Highways.


Occupancy of HDOT rights-of-way by non-project structures or object of any kind or character; also, the activities of other parties within the HDOT rights-of-way.


Good Housekeeping

A common practice related to the storage, use, or cleanup of materials performed in a manner that minimizes the discharge of pollutants.



Chemical compounds that are used to control weeds.

Harbors Tenant

A person, group, partnership, corporation, or any other entity that has an executed lease, revocable permit or disposition instrument under chapter 171, Hawai‘i Revised Statutes (HRS) to use or occupy land, a building, structure, or other property owned by Harbors. This term also includes Harbors’ approved sub-tenants and entities using container or terminal facilities.


Initial Inspection

Inspections conducted on projects that require NPDES coverage, to verify that the construction BMPs identified in the site-specific BMP plan are properly installed and in the correct locations prior to the commencement of ground-disturbing activity.

In-House Project

A construction project that is performed by HDOT personnel. These projects are typically small and maintenance related.

Illicit Discharge

Any discharge to a municipal separate storm sewer that is not composed entirely of stormwater except discharges pursuant to a NPDES permit (other than the NPDES permit for discharges from the municipal separate storm sewer) and discharges resulting from fire fighting activities.

Illegal Connection

Any connection to the Maui District MS4 that is not permitted by a drain connection permit.


Municipal Separate Storm Sewer System (MS4)

A conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, manmade channels, or storm drains) owned by a state, city, town, or other public body, that is designed or used for collecting or conveying storm water, that is not a combined sewer, and that is not part of a publicly owned treatment works [40 CFR 122.26(b)(8)].

MS4 User

Those who perform work upon, perform work adjacent to, or use the HDOT roadways and facilities included in the Maui District MS4 network.

Maui District MS4 NPDES Permit

A General NPDES permit issued by HDOH to HDOT for discharges from the small municipal separate storm sewer system on Kahului, Maui and designated as Permit No. HI15KE674.

Maui District MS4

The small municipal separate storm sewer system owned and operated by HDOT Highways and HDOT Harbors, Maui District, whose boundaries are delineated by the 2010 U.S. Census Urban Area Map.

Maui District

HDOT Highways and HDOT Harbors, Maui District staff and delegated representatives.

Maintenance Projects

Projects that are performed by outside contractors and are overseen by Maui District Highways’ Maintenance Section (HWY-MM). These projects are typically highway maintenance-related.

Maintenance Activities

Routine activities that may require cutting, clearing, grading, or excavation to maintain original line and grade, hydraulic capacity, or original purpose of the facility.



Any substance assimilated by living things that promotes growth. The term is generally applied to nitrogen and phosphorus in wastewater, but is also applied to other essential and trace elements.

Notice of Intent (NOI)

Form completed and signed by a construction site operator or an industrial facility operator notifying the State of Hawaii Department of Health (HDOH) that the operator will comply with an applicable NPDES general permit.

Non-point Source Pollutants

Pollutants that come from many different sources. Unlike pollution from industrial and sewage treatment plants, non-point source pollution is caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters, and even underground sources of drinking water. These pollutants include: Excess fertilizers, herbicides, and insecticides from agricultural lands and residential areas; Oil, grease, and toxic chemicals from urban runoff and energy production; Sediment from improperly managed construction sites, crop and forest lands, and eroding stream banks; Salt from irrigation practices and acid drainage from abandoned mines; Bacteria and nutrients from livestock, pet wastes, and faulty septic systems; and Atmospheric deposition and hydromodification.

National Pollutant Discharge Elimination System (NPDES)

The national program for issuing, modifying, revoking and reissuing, terminating, monitoring and enforcing permits, and imposing and enforcing pretreatment requirements, under Sections 307, 318, 402, and 405 of the CWA.



Refers to the discharge point of a municipal storm sewer system into receiving waters.


Primary Activities

Categories of activities performed by MS4 Users that aid in developing outreach and training activities. Categories include: Driving – Those who drive on roadways, but do not necessarily perform other activities within or adjacent to HDOT rights-of-way. Non-Storm Water Discharger – Those who have the potential to generate non-storm water discharges, listed in HAR 11-55, Appendix K, Part 1.(a), but do not necessarily perform other activities within or adjacent to HDOT rights-of-way. Road Work – Those who perform road work within and adjacent to HDOT rights-of-way. Landscaping – Those who perform landscaping work within and adjacent to HDOT rights-of-way.

Point Source Pollution

Point source pollution is when sources of pollution can be traced to a single point into the receiving water. Point Sources account for over 60 percent of the water pollution in the U.S. today. Industry and domestic sewage treatment plants play a major role in point source pollution. Industrial and domestic waste water and discharges include oils, greases, metals, chemicals, nutrients and sediments.

Permanent BMPs

Storm water BMPs designed to be installed and remain in place as part of the project features to provide long-term storm water quality or quantity control.

Periodic Inspections

Inspections of a contract, in-house, or encroachment project’s construction BMPs by an independent inspector who is not involved in overseeing other aspects of the projects construction.

Performance Measures

Quantitative indicators of how well (or poorly) a program meets a specific objective.


Storm Water

Storm water runoff, and surface runoff and drainage.

State Waters

All waters, fresh, brackish, or salt, around and within the State, including, but not limited to, coastal waters, streams, rivers, drainage ditches, ponds, reservoirs, canals, ground waters, and lakes.


An accidental dumping or spilling of a potential pollutant onto the ground or into a waterway.

Soil Stabilization

Erosion control measures used to minimize erosion.

Site Specific BMP Plan

A plan for controlling pollutants in storm water discharges from sites that meets the requirements of the NPDES for Storm Water Discharges Associated with Construction Activities General Permit.

Sediment Load

Sediment particles maintained in the water column by turbulence and carried with the flow of water.


Organic or inorganic material that is carried by or is suspended in water and that settles out to form deposits in the storm drain system or receiving waters.

Sanitary Sewer

Pipes that carry only domestic waste water, not storm water.


Total Maximum Daily Load (TMDL)

A TMDL establishes the maximum amount of an impairing substance or stressor that a water body can assimilate and still meet Water Quality Standards (WQSs) and allocates that load among pollution contributors. TMDLs are also a tool for implementing State water quality standards. They are based on the relationship between pollution sources and in-stream water quality conditions. A TMDL addresses a single pollutant or stressor for each water body.



The area of land that catches rain and snow and drains or seeps into a receiving water such as marsh, stream, river, lake or ocean.

Water Quality Standards (WQSs)

State adopted and USEPA-approved ambient standards for water bodies. The standards prescribe the use of water body and establish the water quality criteria that must be met to protect water bodies.

Waste Load Allocation

The maximum quantity of pollutants each discharger of waste is allowed to release into a particular waterway as set by an authority. Discharge limits are usually required individually for each specific water quality criterion.