Studying for a Mississippi water or wastewater operator exam? You're in the right place. Pick your discipline below: each tab has the certification levels, how Mississippi names them, and the practice tests that match.
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Choose your certification
How Mississippi classifies drinking-water operators
Mississippi splits operator certification between two agencies: drinking water is the Mississippi State Department of Health, Bureau of Public Water Supply, and wastewater is MDEQ.
Full breakdown in the FAQ below.
Choose your Mississippi certification
Waterworks Operator (Classes E through A, graded by treatment process)
Mississippi Class E, Waterworks Operator Practice Test
Class E covers systems that purchase all their water and add no treatment, and it is also the class for operators whose only job is running the distribution system. High school diploma or GED plus a year at the same class or higher.
MSDH · Class DMississippi Class D, Waterworks Operator Practice Test
Class D is the class for systems whose only treatment is chlorination, fluoridation, or a direct chemical feed such as polyphosphate. A year of experience at the same class or higher, plus the exam.
MSDH · Class CMississippi Class C, Waterworks Operator Practice Test
Class C brings in aeration, pH adjustment, corrosion control and closed pressure filtration including zeolite softening and iron removal. Two years across Class A through D, at least one of them at A, B or C.
MSDH · Class BMississippi Class B, Waterworks Operator Practice Test
Class B is two or more different Class C processes, iron or manganese removal that breaks pressure or needs flocculation or sedimentation, membrane filtration, or ion exchange. Three years across A, B or C with at least one at A or B.
MSDH · Class A (highest)Mississippi Class A, Waterworks Operator Practice Test
Class A is surface water, GWUDI, lime softening, and coagulation and filtration for constituents beyond iron and manganese. Either an engineering or applied science degree plus a year in a Class A plant, or a diploma or GED plus six years. A Class A operator has to be onsite whenever a Class A surface water plant is operating.
Mississippi wastewater practice tests
Wastewater in Mississippi is MDEQ, not MSDH, and it has been mandatory since 1987 under the Municipal and Domestic Water and Wastewater System Operator's Certification Act. Certification runs in Classes I through IV, ascending, so Class IV is the highest. The rule that shapes most people's plans is that Class II must be passed before you may sit Class III or Class IV, which makes Class II the gate rather than a step you can skip. Certificates are valid for three years unless revoked. Exams are offered three times a year and are each preceded by a three or four day preparation course, and MDEQ's study guides are written to be used alongside the Mississippi Wastewater Facilities Operations and Training Manual, with chapter quizzes and a maths section. The training program runs out of the North, Central and South regional offices.
Mississippi Class I, Wastewater Practice Test
Class I is the entry wastewater certification. Note that Mississippi numbers wastewater in Roman numerals I to IV, while drinking water uses letters A to E, so the two ladders do not line up.
MDEQ · Class IIMississippi Class II, Wastewater Practice Test
Class II is the gateway class: MDEQ requires you to pass Class II before you may sit either Class III or Class IV, so it cannot be skipped.
MDEQ · Class IIIMississippi Class III, Wastewater Practice Test
Class III covers advanced biological treatment and solids handling. Class II must already be in hand.
MDEQ · Class IV (highest)Mississippi Class IV, Wastewater Practice Test
Class IV is Mississippi's highest wastewater certification, for the largest and most complex municipal and domestic facilities.
In Mississippi the distribution license is Class E. The classification rule is explicit about it: Class E applies to systems that purchase water only, and "shall also apply to waterworks operators whose only job responsibility is the operation and maintenance of the distribution system(s)". So if you run mains and storage and do no treatment, Class E is the certificate you sit for, and it is the same MSDH exam program as the other classes. It takes a high school diploma or GED and a year of experience at the same class or higher, served under a certified operator who signs off on it. The material below is the distribution body of knowledge that exam draws on.
Mississippi Class E, Distribution Fundamentals
Mains, valves, hydrants, storage and safety basics for a distribution-only operator.
MSDH · Class EMississippi Class E, Distribution Operations
Main disinfection, flushing, cross-connection control and pressure management.
MSDH · supplementaryMississippi Distribution, Advanced Practice
Hydraulics, pumping and storage operation, and distribution system water quality. Useful if your system also holds a treatment class.
MSDH · supplementaryMississippi Distribution, Large System Practice
System-wide planning, capital work and regulatory compliance across a large distribution network.
MDEQ's certification regulation is written for "Municipal and Domestic Wastewater Facility Operators", and Mississippi does not appear to issue a collection-system certificate that is separate from the Class I to IV facility ladder, the way Minnesota does with its Type S classes or Michigan now does under Part 41. Confirm your own situation with MDEQ, because the requirement follows the facility you are responsible for. Either way the collection body of knowledge below is worth working through: sewers, lift stations and inflow and infiltration all sit inside the wastewater exams, and collection work is where most municipal operators actually spend their time.
Mississippi Collection Systems, Entry Level Practice
Pipe, manholes, basic maintenance, safety and confined space awareness.
MDEQ · supporting materialMississippi Collection Systems, Operating Level Practice
Cleaning and inspection, lift station operation, infiltration and inflow, overflow response.
MDEQ · supporting materialMississippi Collection Systems, Senior Level Practice
Pump station hydraulics, force mains, odor and corrosion control, rehabilitation methods.
MDEQ · supporting materialMississippi Collection Systems, Manager Level Practice
Asset management, capacity assurance, capital planning and regulatory reporting.
About the Mississippi operator exams
Operator certification in Mississippi covers several disciplines, drinking water, wastewater, distribution, and collections, which may be handled by the same agency or by separate programs (drinking water is administered by MSDH (Mississippi State Department of Health), Bureau of Public Water Supply, and MDEQ (Mississippi Department of Environmental Quality) for wastewater). The exact certification structure, exam format, levels, and continuing-education requirements vary by discipline and change over time, so always confirm the current scope and eligibility directly with the certifying agency. Our practice content focuses on the underlying technical material: the same operating principles, math, regulations, and process knowledge that show up on water and wastewater operator exams nationwide.
Frequently asked questions
How does Mississippi classify water operators?
Are these the exact questions on the Mississippi exam?
Are these practice tests free?
Disclaimer: WaterOperatorPracticeTest.com is an independent study aid. We are not affiliated with MSDH (Mississippi State Department of Health), Bureau of Public Water Supply, and MDEQ (Mississippi Department of Environmental Quality) for wastewater or any state primacy agency. Always confirm current exam requirements with your state's certification body.