By what means is biological sewage treatment...

🔍 Key Concepts

• 33 CFR Part 159 – Marine sanitation devices (MSDs) requirements for Type II biological treatment units • Purpose of disinfection after biological treatment (what problem are we still trying to solve?) • Common shipboard disinfection methods: chlorination (hypochlorite) vs ultraviolet (UV) irradiation

💭 Think About

• Ask yourself: Does the Coast Guard typically allow more than one approved method for disinfecting sewage effluent, or just one very specific method? • Think about which methods are practical and commonly installed on ships’ sewage treatment plants you’ve seen or studied. • Consider whether a biological treatment plant can legally discharge without any disinfection when it’s operating properly.

✅ Before You Answer

• Verify in 33 CFR 159 whether disinfection is still required for biological treatment plants before discharge. • Check which disinfection methods are explicitly recognized for marine sanitation devices (is UV included, is hypochlorite included, or both?). • Confirm whether any option claiming "only" one method matches what you’d reasonably expect for approved shipboard equipment.

By what means is biological sewage treatment plant effluent disinfected before discharge overboard?

Disinfection is not required on biological sewage treatment plants.

Ultraviolet light irradiation is the only approved means of disinfection.

Hypochlorite tablets or liquid solution and ultraviolet irradiation are both approved means of disinfection.

Hypochlorite tablets or liquid solution is the only approved means of disinfection.

🔍 Key Concepts

💭 Think About

✅ Before You Answer