What the Course Entails and Exam Details

This targeted preparation resource focuses entirely on the critical water-related competencies required for the REHS/RS credential. Candidates must demonstrate comprehensive knowledge across these areas:

Potable Water Supply and Quality

• Source Water Protection: Understanding groundwater and surface water hydrology, geology, and methods to prevent contamination of drinking water sources.

• Treatment Processes: Detailed knowledge of coagulation, flocculation, sedimentation, filtration, and disinfection methods (e.g., chlorination, UV, ozone) for public and individual systems.

• Distribution and Storage: Regulations and best practices for system design, cross-connection control, backflow prevention, and maintaining chlorine residuals.

• Monitoring and Sampling: Compliance with the Safe Drinking Water Act (SDWA), sampling techniques for microbiological and chemical contaminants, and interpreting lab results.

Wastewater Management and Treatment

• Onsite Wastewater Treatment Systems (OWTS): Soil science basics, site evaluation (perc tests), design and inspection of septic tanks, absorption fields, and advanced treatment units.

• Municipal Wastewater Treatment: Understanding primary, secondary (activated sludge, trickling filters), and tertiary treatment stages.

• Collection Systems and Maintenance: Basics of sewer design, lift stations, and managing inflow/infiltration (I&I).

• Residuals Management: Regulations for the treatment, beneficial reuse, and disposal of sewage sludge and biosolids.

What to Expect in the Final Exam

The full REHS/RS examination is a rigorous assessment administered by NEHA. To succeed, candidates must understand the final exam structure:

• Exam Format: The REHS/RS exam consists of 225 multiple-choice questions.

• Time Limit: Candidates are allowed a total of four (4) hours to complete the entire examination.

• Scoring: NEHA uses a scaled scoring system. While the raw score needed to pass can vary slightly depending on the difficulty of the specific exam form, the scaled passing score is consistently set at 650.

• Domain Weighting: The water-related domains represent a significant portion of the total exam. While the exam covers many environmental health topics (e.g., food safety, institutions), the combined weighting for Potable Water and Wastewater usually falls between 20% and 30% of the total raw score, making mastery of these topics non-negotiable.

How to Study and Exam Centers

Preparation for the REHS/RS exam requires a structured approach and dedication. Use these strategies:

• Utilize the NEHA Study Guide: The REHS/RS Study Guide (currently in its 5th edition) is an indispensable resource. It provides comprehensive outlines of all domains and suggested references for deep study.

• Focus on the References: NEHA lists the source texts used to develop the exam questions. Prioritize reading key EPA manuals on small water systems and onsite wastewater treatment.

• Practice with Purpose: Do not just memorize answers. Use practice tests, like this one, to identify your weak points in specific areas, such as calculating dosage or interpreting soil logs.

Where to Take the Exam

The REHS/RS exam is offered globally. Candidates have flexible options for scheduling:

• Pearson VUE Testing Centers: This is the most common method. Once NEHA approves your application, you will receive an authorization to test (ATT) letter, allowing you to schedule your exam at any authorized Pearson VUE professional testing center worldwide.

• NEHA Annual Educational Conference (AEC): NEHA typically offers in-person testing in conjunction with their annual conference.

Job Opportunities from the Course

Earning the REHS/RS credential dramatically improves job prospects and career mobility. The certification is recognized across public and private sectors.

Potential job titles and career paths enabled by this certification include:

• Environmental Health Specialist (Local, State, or Federal Government)

• Registered Sanitarian

• Public Health Inspector

• Water Quality Specialist (Municipal Utilities)

• Environmental Compliance Officer

• Onsite Wastewater Inspector/Designer

• Environmental Health Consultant (Private Sector)

• Consumer Safety Officer (FDA/USDA)