Chemistry and Biology of Natural Waters

Course Description

Chemistry and Biology of Natural Waters and Laboratory is an introductory course giving an overview of the biological and chemical components of natural water systems, their importance to Earth's ecosystems, and the analysis techniques used to monitor them.

Within the SCNS taxonomy, EVS is the Environmental Science prefix and the C suffix marks an integrated lecture-and-laboratory course. Daytona State publishes this at 4 credits, offered spring, with an $88.29 lab fee and prerequisites MAT1033 or higher, OCE1001, BSC1005, and CHM1025C. Contact hours are approximately 90, matching the combined published EVR2001 (3 cr / 45 hrs) and EVR2001L (1 cr / 45 hrs) lecture-plus-laboratory pair at the same college and the same total credit value.

Florida is an unusually good place to study this. The state's identity is water — springs, rivers, lakes, wetlands, estuaries, a shallow aquifer supplying most of its drinking water, and two coasts — and it is also the site of some of the most visible water quality problems in the country. The material in this course is not abstract here; it is the science underneath news stories that run every year.

Learning Outcomes

Required Outcomes

• Describe the properties of water that make it biologically and chemically distinctive.
• Describe the hydrologic cycle and the major categories of natural water systems.
• Describe the physical structure of lakes, including stratification and turnover.
• Describe estuarine circulation and the behaviour of salinity gradients.
• Measure and interpret temperature, pH, conductivity, salinity, and turbidity.
• Describe dissolved oxygen dynamics, saturation, and the causes of hypoxia.
• Describe the carbonate system, alkalinity, and buffering in natural waters.
• Describe the nitrogen cycle in aquatic systems and its principal forms.
• Describe the phosphorus cycle and the concept of limiting nutrients.
• Describe organic carbon, biochemical oxygen demand, and their measurement.
• Describe major ions, hardness, and the chemistry of groundwater interaction.
• Describe metals and trace contaminants in aquatic systems.
• Describe primary production, phytoplankton, and periphyton.
• Describe aquatic food webs and trophic structure.
• Describe benthic macroinvertebrates and their use as biological indicators.
• Describe eutrophication, its causes, and its consequences.
• Describe harmful algal blooms, the organisms involved, and their toxins.
• Describe point and non-point source pollution and their relative contributions.
• Design a sampling plan appropriate to a monitoring question.
• Collect water samples using correct technique, preservation, and chain of custody.
• Perform standard laboratory analyses and calibrate instruments correctly.
• Apply quality assurance and quality control procedures, including blanks and duplicates.
• Analyze, graph, and interpret water quality data and compare it to standards.
• Report monitoring results in professional written form.

Optional Outcomes

• Describe Florida spring systems and their particular vulnerabilities.
• Describe wetland biogeochemistry.
• Describe drinking water treatment and distribution chemistry.
• Describe wastewater treatment processes.
• Describe emerging contaminants including pharmaceuticals, microplastics, and PFAS.
• Describe stormwater management and low impact development.
• Participate in a citizen science or volunteer monitoring programme.

Major Topics

Required Topics

• Properties of water
• The hydrologic cycle and water system types
• Lake structure, stratification, and turnover
• Estuarine circulation and salinity
• Physical parameters: temperature, pH, conductivity, salinity, turbidity
• Dissolved oxygen and hypoxia
• The carbonate system, alkalinity, and buffering
• The nitrogen cycle
• The phosphorus cycle and limiting nutrients
• Organic carbon and biochemical oxygen demand
• Major ions, hardness, and groundwater chemistry
• Metals and trace contaminants
• Primary production and phytoplankton
• Aquatic food webs
• Benthic macroinvertebrates as indicators
• Eutrophication
• Harmful algal blooms and toxins
• Point and non-point source pollution
• Sampling design
• Field sampling technique, preservation, and chain of custody
• Laboratory analysis and instrument calibration
• Quality assurance and quality control
• Data analysis and comparison to standards
• Technical reporting

Optional Topics

• Florida spring systems
• Wetland biogeochemistry
• Drinking water treatment
• Wastewater treatment
• Emerging contaminants: pharmaceuticals, microplastics, PFAS
• Stormwater and low impact development
• Citizen science and volunteer monitoring

Resources & Tools

• Standard Methods for the Examination of Water and Wastewater (APHA/AWWA/WEF) — the analytical authority; every method you use in the laboratory traces back to it.
• Limnology (Wetzel) or Fundamentals of Limnology — the standard reference for inland waters.
• Aquatic Chemistry (Stumm & Morgan) — the definitive text; demanding, and worth knowing exists.
• Water Quality (Boyd) or Chemistry for Environmental Engineering and Science (Sawyer) — more accessible working texts.
• EPA Water Quality Standards and analytical methods (epa.gov) — free and authoritative, including approved methods under 40 CFR Part 136.
• Florida DEP — free: Chapter 62-302 F.A.C. surface water quality standards and classifications, the impaired waters and TMDL programmes, and Basin Management Action Plans. These are the standards Florida data is actually compared against.
• Florida DEP Watershed Information Network and WIN/STORET — free access to real Florida monitoring data you can analyze.
• USGS National Water Information System — free real-time and historical streamflow and water quality data.
• Florida Fish and Wildlife Research Institute — free red tide status reports and HAB monitoring.
• St. Johns River, Southwest Florida, and South Florida Water Management Districts — free regional data, reports, and a significant source of internships and jobs.
• Florida LAKEWATCH (UF/IFAS) — a long-running free volunteer monitoring programme; participating is genuine experience and looks real on a résumé.
• R or Python — free; water quality data analysis is increasingly done in them, and it is a differentiating skill.

Career Pathways

• Water quality technician — SOC 19-4042; the direct destination.
• Environmental laboratory analyst — commercial and municipal laboratories; steady work with regular hours.
• Field sampling technician — consulting firms, agencies, and water management districts.
• Water and wastewater treatment plant operator — Florida licenses operators through DEP, the pay is solid, the work is stable, and there is a genuine statewide shortage. This is one of the most reliable technical careers in the state and it is badly under-advertised.
• Water management district staff — the five districts are major Florida employers of exactly this training.
• Florida DEP and county environmental programmes.
• Environmental consulting — often paired with the site assessment work covered in this repository's EVR2647 guide.
• Stormwater and utilities — municipal stormwater programmes have regulatory monitoring obligations.
• Aquaculture and fisheries support.
• Marine science and research technician roles — Florida's marine institutes and university laboratories.
• Continuation to a B.S. in environmental science, marine science, biology, or chemistry.

Special Information

⚠ The data is only as good as the sample — QA/QC is the actual subject

• Most water quality errors happen before the sample reaches the instrument. Contaminated bottles, wrong preservative, exceeded holding time, and sampling in the wrong place all produce numbers that look fine and mean nothing.
• Sampling design determines what the data can answer. Where, when, how deep, how often, and how many — a single grab sample from a bridge tells you about one moment at one point, and treating it as characterizing a water body is a category error.
• Natural waters vary on every time scale. Dissolved oxygen swings substantially between dawn and afternoon because of photosynthesis and respiration; a single midday DO reading can miss the pre-dawn minimum that actually kills fish. Sample timing is a scientific decision.
• Some parameters must be measured in the field — temperature, pH, dissolved oxygen, and conductivity all change on the way to the laboratory.
• Preservation and holding times are method requirements, not suggestions, and each analyte has its own.
• Run your blanks and duplicates. A field blank detects contamination introduced by your own procedure; duplicates measure precision. Students skip these and then cannot defend an anomalous result.
• Calibrate before every use and document it. An uncalibrated meter produces confident, precise, wrong numbers.
• Chain of custody matters whenever data may be used in a regulatory or legal context, which in this field is often.
• Detection limits are part of the result. A non-detect at a reporting limit above the standard answers nothing, and reporting it as "clean" is wrong.
• Record field conditions — recent rain, wind, tide stage, visible algae, odour. Context is what makes numbers interpretable months later.

⚠ Nutrients and eutrophication — the central problem of Florida water quality

• Eutrophication is nutrient enrichment driving excessive plant and algal growth, and its consequences follow predictably: algal blooms, reduced light penetration, seagrass and submerged vegetation loss, oxygen depletion as the blooms decay, and fish kills.
• The limiting nutrient concept explains why management targets differ. Phosphorus commonly limits freshwater systems and nitrogen commonly limits marine and estuarine ones, though Florida systems are frequently co-limited and the answer is system-specific.
• Non-point sources dominate. Fertilizer runoff from lawns and agriculture, septic system leachate, and stormwater collectively contribute far more than permitted discharges in most Florida watersheds — and they are far harder to regulate because there is no pipe to permit.
• Septic systems are a major and underappreciated Florida nitrogen source, particularly in the spring recharge basins and along the Indian River Lagoon, and conversion to sewer is a recurring and expensive policy fight.
• Florida's springs are the clearest illustration. Historically clear, high-flow systems have shown rising nitrate concentrations and shifts from native vegetation toward filamentous algae, and the nitrate arrives through the aquifer from land uses across a wide recharge area.
• The Indian River Lagoon and Lake Okeechobee are the highest-profile Florida cases, with seagrass loss, manatee mortality, and discharge-driven downstream blooms all traceable to nutrient loading.
• Regulatory response runs through TMDLs and Basin Management Action Plans under the Clean Water Act and Florida statute, with numeric nutrient criteria a long-contested area. Rule 11 applies — standards, criteria, and BMAP requirements change; verify with DEP.
• Legacy nutrients delay recovery. Phosphorus stored in sediments continues to cycle for years after inputs are reduced, which is why improvement lags action and why management patience is required.

⚠ Harmful algal blooms: Florida's most visible water quality issue

• Florida red tide is Karenia brevis, a marine dinoflagellate producing brevetoxins. Blooms occur naturally offshore and are transported inshore, where nutrients can intensify and prolong them — the relationship between nutrient loading and red tide is real but more complicated than headlines suggest, and this distinction is worth getting right.
• Brevetoxins aerosolize. Wave action puts them into sea spray, causing respiratory irritation onshore — an unusual property among algal toxins, and the reason red tide closes beaches.
• Neurotoxic shellfish poisoning results from consuming affected shellfish, and shellfish harvest closures during blooms are a public health measure.
• Freshwater cyanobacteria blooms — Microcystis and others — produce microcystins and other toxins affecting liver and nervous system, and are a recurring problem in Lake Okeechobee and the connected river systems.
• Cyanotoxins are a drinking water concern, and conventional treatment does not reliably remove them; some treatment steps can make matters worse by lysing cells and releasing intracellular toxin.
• Do not swim in, or let pets near, a visible bloom. Dog deaths from cyanotoxin exposure are documented and rapid.
• Economic consequences are large — tourism, fisheries, and property values all respond to blooms, which is why Florida invests heavily in monitoring.
• FWC's Fish and Wildlife Research Institute publishes free current bloom status, and its data is usable for coursework.
• Rule 11 applies — HAB science, toxin thresholds, and health advisories are actively developing.

⚠ Florida's hydrogeology makes the chemistry distinctive

• The Floridan aquifer is limestone, which makes Florida groundwater characteristically hard and highly buffered, dominated by calcium and bicarbonate. Alkalinity here is naturally high, and that changes how systems respond to acid inputs.
• Karst means rapid connection between surface and groundwater. Sinkholes, swallets, and conduits move water — and contaminants — far faster than porous-media flow, which undermines assumptions built into standard groundwater models.
• Springs are groundwater made visible, and their chemistry reports on the aquifer's condition across a wide recharge area. That is what makes them such good sentinels.
• Blackwater rivers — the Suwannee, Santa Fe, and many smaller systems — are naturally acidic and darkly stained by dissolved organic carbon, and applying general expectations to them produces wrong conclusions.
• Saltwater intrusion is a live coastal concern driven by groundwater withdrawal and sea level, and conductivity monitoring is how it is tracked.
• Estuaries are chemically dynamic — the Indian River Lagoon, Tampa Bay, and Charlotte Harbor all show strong salinity, nutrient, and oxygen gradients that vary with tide, wind, and freshwater inflow.
• The wet and dry season cycle drives Florida water quality more than temperature does; sampling in June and December can give entirely different pictures of the same system.
• Tampa Bay is the encouraging case. Nitrogen load reductions produced substantial seagrass recovery over decades — evidence that this science, applied consistently, works.

⚠ Field and laboratory safety

• Water safety first. Wear a PFD on boats and around deep or moving water, and never wade a current you have not assessed.
• Florida field hazards are real — alligators, venomous snakes, fire ants, mosquitoes and the diseases they carry, and above all heat. Hydrate deliberately and recognize heat illness in yourself and others.
• Contaminated water carries pathogens. Cover cuts, avoid contact with waters under a health advisory, and wash thoroughly afterwards.
• Laboratory reagents include strong acids and toxic compounds. Read the safety data sheets, use the fume hood, wear eye protection, and know where the eyewash and shower are.
• Acid preservation is the routine hazard in water analysis — add acid to water, never the reverse.
• Never work alone in the field without a check-in protocol, and file a plan before you go.

How Florida course levels affect transfer

The first digit of an SCNS number denotes the year of offering, not transferability. Courses at the 1000 and 2000 levels transfer transparently between Florida public institutions, and 3000 to 4000 is unproblematic since both are upper division. The boundary that actually matters is 2000 to 3000, where lower-division credit generally cannot satisfy an upper-division requirement.

EVS2026C is 4 credits and approximately 90 contact hours, offered spring with an $88.29 lab fee. Expect substantial laboratory work with formal reports and probable field sampling. The prerequisite set — algebra, oceanography, biology, and chemistry — is unusually broad and is genuinely used; students missing the chemistry in particular find the analytical content hard.

As a 2000-level C-suffixed course it transfers on the ordinary lower-division basis, and integrated lecture-plus-laboratory science courses generally satisfy laboratory science general education requirements — but confirm with your receiving institution, since the C suffix is part of the course number and equivalency does not cross it.