Protecting public health and the environment by managing how water moves, is treated, and is returned to nature.
Environmental and water resources engineering is the discipline of safeguarding public health and the natural environment by understanding, controlling, and improving the movement and quality of water, air, and waste — designing the systems that deliver safe drinking water, clean wastewater, manage stormwater and floods, and keep pollutants out of the air, soil, and groundwater on which communities depend.
Environmental and water resources engineering applies the principles of fluid mechanics, chemistry, biology, and hydrology to protect people and ecosystems. Where a chemical engineer optimizes a product, the environmental engineer optimizes outcomes for public health and the environment: water that is safe to drink, effluent clean enough to return to a river, a watershed that does not flood, and air and land that do not poison the people who live there. The unifying ideas are the conservation of mass applied to pollutants, the hydrologic cycle that moves water through the landscape, and the chemistry and biology that transform contaminants from harmful to harmless.
The field rests on a set of connected pillars. Hydrology describes how rainfall becomes runoff, recharge, and streamflow, and underpins flood and water-supply design. Open-channel and pressurized hydraulics — Manning’s equation for rivers and channels, Hazen-Williams and Darcy-Weisbach for pipes — govern how water is conveyed. Stormwater management controls the quantity and quality of runoff from developed land using the rational method, detention basins, and modern green-infrastructure practices. Drinking-water treatment removes pathogens, turbidity, and chemical contaminants through coagulation, sedimentation, filtration, and disinfection. Wastewater treatment uses physical, biological, and chemical processes (primary settling, activated sludge, nutrient removal, disinfection) to clean sewage before discharge. Water-quality chemistry — BOD, dissolved oxygen, nutrients, pH, and disinfection by-products — quantifies how clean water is and must be. Groundwater and hydrogeology, governed by Darcy’s law, address aquifers, wells, and contaminant transport and remediation. Air quality and solid-waste engineering extend the same mass-balance and treatment thinking to emissions, landfills, and resource recovery. Threading through all of it is a dense framework of environmental regulation and compliance that translates science into enforceable limits.
The hydrologic cycle, rainfall-runoff relationships, design storms and return periods, peak-flow estimation, streamflow, and water-supply and flood analysis.
Manning’s equation for open channels, Hazen-Williams and Darcy-Weisbach for pressurized pipe flow, weirs and flumes, energy and momentum, and pump systems.
The rational method, storm-sewer and culvert design, detention and retention basins, water-quality treatment, and green-infrastructure best management practices.
Coagulation and flocculation, sedimentation, filtration, disinfection and CT compliance, softening, and meeting Safe Drinking Water Act standards.
Preliminary and primary treatment, activated sludge and attached-growth biological processes, nutrient removal, secondary clarification, disinfection, and solids handling.
BOD and dissolved oxygen, nutrients and eutrophication, pH and alkalinity, chlorine chemistry and disinfection by-products, and unit conversions (mg/L, ppm, MGD).
Aquifers and Darcy’s law, hydraulic conductivity and gradient, well hydraulics and capture zones, contaminant transport, and remediation.
The Safe Drinking Water Act and Clean Water Act, NPDES discharge permitting, 10 States Standards, and AWWA/WEF design guidance — plus air-quality and solid-waste rules.
An environmental engineer designs and manages the systems that protect public health and the environment — drinking-water and wastewater treatment plants, stormwater and flood-control systems, groundwater remediation, and air-quality and solid-waste controls. Day to day that means running hydrologic and hydraulic analyses, sizing treatment unit processes, modeling water quality, and ensuring designs comply with EPA and state regulations. Many use tools like EPANET, SWMM, and HEC-RAS to model water systems.
Environmental engineering grew out of civil engineering and the two overlap heavily — both deal with water, infrastructure, and public works. Civil engineering is broad (structures, transportation, geotechnical, water resources), while environmental engineering specializes in protecting health and the environment: water and wastewater treatment, water quality, air pollution, and waste management. Water resources sits in the overlap, and many engineers hold a PE in either Civil (Water Resources & Environmental) or Environmental.
Conventional drinking-water treatment passes raw water through coagulation and flocculation (to clump fine particles), sedimentation (to settle them out), filtration (to remove remaining particles), and disinfection — usually chlorination, sometimes UV or ozone — to inactivate pathogens. The disinfection step must meet a "CT" requirement (concentration multiplied by contact time) to guarantee pathogen kill, and treated water must satisfy the EPA’s National Primary Drinking Water Regulations under the Safe Drinking Water Act.
Biochemical oxygen demand (BOD) measures how much dissolved oxygen microorganisms consume while breaking down the organic matter in water, typically over five days (BOD5). It is the headline indicator of wastewater strength and pollution: high-BOD discharge into a river depletes dissolved oxygen and can kill fish and aquatic life. Wastewater treatment is designed to reduce BOD to permit limits before discharge, and NPDES permits set the allowable BOD load.
Yes. NCEES offers the FE Environmental exam (the first step, usually taken near graduation) and the PE Environmental exam for licensure after about four years of qualifying experience. The PE is highly valued in this field because much environmental and water-resources work — treatment plants, stormwater systems, discharge permits — is public-facing infrastructure that requires a licensed engineer to stamp the designs. Many environmental engineers also pursue a PE in Civil with a Water Resources & Environmental focus.