Water Sources, Hydrology, and Source Water Protection
The Water Sources, Hydrology, and Source Water Protection domain tests whether you can identify a system's source, explain how water moves to it, and apply protection measures before treatment. Kentucky systems include large river intakes, reservoirs, springs, and wells, so questions mix basic hydrology with state and federal protection requirements.
Core rules and concepts
- Surface water is exposed to runoff, upstream discharges, algae, and turbidity. Intake placement should avoid short-circuiting and sediment beds.
- Groundwater moves through aquifers; pumping lowers the water table and creates a cone of depression that can capture nearby contamination.
- Groundwater under the direct influence of surface water (GWUDI) must be evaluated. If confirmed, the source is treated and monitored as surface water.
- A source water assessment delineates the protection area, inventories potential contaminant sources, and rates susceptibility. Kentucky assessments are available through the Division of Water.
- Wellhead protection manages the land area contributing to a well: chemical storage, setbacks, abandoned wells, septic systems, and spill response.
- Sanitary surveys identify source and treatment vulnerabilities and set corrective actions.
Worked example
A well pumps from an aquifer with hydraulic conductivity 50 ft/day, gradient 0.002, and porosity 0.25. What is the approximate 5-year contaminant travel distance? Darcy velocity = K × i = 50 × 0.002 = 0.1 ft/day. Seepage velocity = 0.1 ÷ 0.25 = 0.4 ft/day. Five years = 1,825 days. Distance = 0.4 × 1,825 = 730 ft. The seepage velocity is used because contaminants travel through pore spaces, not the whole aquifer cross-section.
Traps that cost marks
Using Darcy velocity instead of seepage velocity; assuming springs are automatically safe; ignoring upstream discharges; confusing a source water assessment with a compliance sample; forgetting that GWUDI changes treatment and monitoring.