Email Us

(888) 397-9414

9:00am EST–4:00pm PST

Office Hours

M–F, 9:00am–4:00pm EST


Email Us

(888) 397-9414

9:00am EST–4:00pm PST

Office Hours

M–F, 9:00am–4:00pm EST

Frequently Asked Questions

  • Where do I find the exact location of my class?

    Since the start of COVID-19 our classes have been conducted via webinar.  

  • How long is CSI certification valid?

    Your CSI certification is valid for five (5) years.  Graduates may take our CSI-Recertification webinar to extend their credentials for an additional five (5) years. Classes that offer certification are:



    CSI-Puerto Rico

    CSI-Construction Permits

    CSI-Construction Controls

    CSI-Industrial Permittees and MS4 Personnel

  • Does certification mean that I am qualified?

    Our CSI classes provide you with certification credentials, which indicate that the services a graduate conducts are being performed by a professional who has met the established standards of knowledge, experience, and competence required in the field of stormwater inspections.  Your regulatory permit requires that the person who signs your NPDES permit and reports must select "qualified personnel" to manage the stormwater program.  Qualification must be determined by your organization, however, we believe that our certification helps better position you as being "qualified."

  • Is certification valid only in the state where I received training?

    National Stormwater Center trains stormwater inspectors across the country, including U.S. territories.  Your CSI certification is valid in any state plus U.S. territories.

  • I took CSI-Construction Permits and CSI-Construction Controls. Does my CSI certification qualify me for other training programs?

    Probably not. Examples would be states who have mandatory Erosion and Sediment Control courses, which many states now have. A distinction is that our courses focus on the water, while most E&SC courses focus on the dirt. If you control the volume and velocity of water on / from your site, you can control dirt, erosion, and sedimentation. Regardless of your stance, if a state has mandatory Erosion and Sediment Control courses, you must take those classes and receive a passing grade to work on construction and development projects in those states.

    The one exception is that National Stormwater Center does provide training for Florida's mandatory E&SC program. You can click this link to find these courses.

  • Is it possible to have a private CSI class?

    Yes. We can conduct private webinars or private on-site or off-site classes. Simply contact our business office - we will be happy to work with you to set up a private class for your staff.

  • Do you offer pricing discounts?

    Yes. We offer discounts for multiple registrants from the same organization.  Each class offering describes pricing and and discounts in detail. For large groups (10+ students), you may call our business office at any time to discuss further potential discounts.


Stormwater Acronyms

It has been said that the NPDES Stormwater program has more acronyms than any branch of the military! Here is our attempt to clear up any murky waters. This is a work in progress and we encourage you to send us additional acronyms that should be added.

303(d) list = Impaired Waters of the US

States are required to submit their list of impaired waters for EPA approval every two years. For each water on the list, the state identifies the pollutant causing the impairment, when known. In addition, the state assigns a priority for development of Total Maximum Daily Loads (TMDLs) based on the severity of the pollution and the sensitivity of the uses to be made of the waters, among other factors (40 C.F.R. §130.7(b)(4)).

BMP = Best Management Practice

BMPs are controls, processes, policies, and/or tools to prevent the discharge of pollutants in stormwater. Examples of BMPs include, but are not limited to: staff training, preventing exposure of pollutant sources, and clearly identifying contents of outdoor containments (such as barrels).

CAFO=Concentrated Animal Feeding Operation

Lot or facility (other than an aquatic animal production facility) subject to NPDES permitting where:

  • animals have been, are, or will be stabled or confined and fed or maintained for a total of 45 days or more in any 12-month period, and
  • crops, vegetation, forage growth, or post-harvest residuals are not sustained in the normal growing season over any portion of the lot or facility.

CSO = Combined Sewer Overflow

Combined sewer systems are designed to collect stormwater runoff and domestic sewage in the same pipe. Most of the time, combined sewer systems transport all of their wastewater to treatment.

CWA = Clean Water Act

The Clean Water Act is the primary federal law in the United States governing water pollution. Its objective is to restore and maintain the chemical, physical, and biological integrity of the nation's waters.

FOG = Fats, Oils, Grease

FOG occurs when cooking fats are poured down the drain and coat the inside of the pipes, eventually forming a blockage. Food processing is a primary source of FOG.

GP= General Permit

A permit issued to a class or category of dischargers such as construction stormwater, industrial stormwater, or small municipal separate storm sewer systems. Dischargers may or may not be required to formally request to be covered under GPs.

IDDE = Illicit Discharge Detection and Elimination

One of the 6 minimum control measures defined in MS4 stormwater permits, illicit discharges are “...any discharge to an MS4 that is not composed entirely of stormwater,” with some exceptions.

LEED Certification = Leadership in Energy and Environment Design

The U.S. Green Building Council, a nonprofit that certifies environmentally sustainable businesses, homes, hospitals, schools, and neighborhoods, also issues LEED certification.

LID = Low Impact Development (also referred to as Green Development)

LID is a design approach to manage stormwater runoff as part of green infrastructure. LID emphasizes conservation and use of on-site natural features to protect water quality. This approach implements engineered hydrologic controls to replicate pre-development hydrology.

LOS/EOS/COS = Level of Service / Extent of Service / Cost of Service

Utilities generally need to determine and document these measures and provide them to their customers.

MCM = Minimum Control Measures

Small MS4s are required to implement the 6 MCMs as a condition of their NPDES permit. The 6 MCMs are:

  1. Public Involvement and Public Participation
  2. Public Education and Public Outreach
  3. Illicit Discharge Detection and Elimination
  4. Construction Controls
  5. Post Construction Controls
  6. Good Housekeeping

MEP = Maximum Extent Practicable

Stormwater permits require the reduction of pollutants in stormwater discharges to the MEP, including management practices, control measures, and system design and engineering methods.

MS4 = Municipal Separate Storm Sewer System

A municipal separate storm sewer system (MS4) is a publicly-owned conveyance or system of conveyances (including but not limited to streets, ditches, catch basins, curbs, gutters, and storm drains) that is designed or used for collecting or conveying stormwater, and that discharges to surface waters of the State. These public entities include ports, prison complexes, park districts, universities, or diking and drainage districts.

NOI = Notice of Intent

A NOI is a stormwater permit application.

NOT=Notice of Termination

A NOT is a formal notice that a permittee is no longer authorized to discharge stormwater. A NOT can be issued by a regulatory authority or it can be applied for by a permittee.

NOC =Notice of Coverage

Notification from a permit authority that a stormwater source is covered under a general permit.

NPDES = National Pollutant Discharge Elimination System

The NPDES permit program addresses water pollution by regulating point sources that discharge pollutants to waters of the United States.

Some states exchange “N(ational)” to brand their permit program:

  • IPDES=Idaho Pollutant Discharge Elimination System
  • LPDES=Louisiana Pollutant Discharge Elimination System
  • SPDES=(New York) State Discharge Elimination System
  • TPDES=Texas or Tennessee Pollutant Discharge Elimination System

However a regulatory authority may brand their program, it remains a system to eliminate the discharge of pollutants nationally.

NTU = Nephelometric Turbidity Units

Turbidity is the cloudiness or haziness of water. High turbidity results in water that is less clear. NTUs are the degree to which light is scattered by suspended particles in the water.

POC= Pollutant of Concern

This usually refers to specific pollutants threatening or impairing a particular waterbody. For stormwater sources, POCs are often silt, bacteria, nutrients, or toxics.

P2 = Pollution Prevention

Pollution prevention (P2) is any practice that reduces, eliminates, or prevents pollution at its source, also known as "source reduction."

P2Rx = Pollution Prevention Resource Exchange

The P2Rx is a national partnership of regional pollution prevention information centers funded in part through grants from EPA.

P2Rx delivers pollution prevention information and measures program results by state, by area of expertise, and by program type. They provide a wealth inform of pollution prevention information for businesses, government agencies, not for profits, schools, and the general public.

SCM – Stormwater Control Measure

Same as BMP.

SIC = Standard Industrial Classifications

A system for classifying industries by a four-digit code. Stormwater permits use SIC codes to designate the 29 industrial activities subject to NPDES permitting, and define regulations specific to each activity.

SMP or SWMP = Stormwater Management Plan

SMPs/SWMPs are, in essence, SWPPPs for municipalities. They are written documentation submitted as required for stormwater discharges from MS4s that describe how the program will be implemented, managed, and measured.

SSO = Sanitary Sewer Overflows

Sanitary sewer overflow (SSO) is the discharge of sewage into the environment before it can reach treatment facilities.

SWPPP = Stormwater Pollution Prevention Plan (also referred to as SWP3)

SWPPPs are site-specific documents required by Construction and Industrial stormwater permits to:

  • identify potential sources of stormwater pollution on a construction, industrial and/or municipal site;
  • describe stormwater control measures and Best Management Practices (BMPs) that will be used to reduce or eliminate pollutants in stormwater discharges from the project site; and,
  • identify the procedures the operator of the site will implement to comply with the terms and conditions of the permit.

Permits define requirements of the SWPPP.

TMDL = Total Maximum Daily Load

TMDLs describe a plan for restoring impaired waters by identifying and allocating the maximum amount of a pollutant that a body of water can receive while still meeting water quality standards. TMDL allocations are established for all sources that discharge an impairment-causing pollutant to a waterbody.

VGP = Vessel General Permit

Implemented jointly by EPA and the U.S. Coast Guard, this program provides NPDES permit coverage for discharges into waters of the United States from commercial (non-military and/or non-recreational) vessels greater than 79 feet in length, and for ballast water from commercial vessels of all sizes. Approximately 61,000 domestically flagged vessels and 8,000 foreign flagged vessels require VGP permit coverage.