Exercise : Mitigate Sewage spills and Improve Low Quality Water

Jul 2

4 min read

Mitigating sewage spills and improving low water quality requires a dual approach: enforcing aggressive infrastructure upgrades and utilizing real-time tracking to avoid exposure.

I. Mitigation

The mitigation of sewage spills and low water quality involves a combination of direct community, regulatory, and infrastructural measures:

Real-time Monitoring & Avoidance: Public health can be protected by checking daily alerts. You can track real-time spills and pollution warnings using the Surfers Against Sewage Safer Seas & Rivers Service to avoid recreational contact with compromised waterways.
Infrastructure Overhauls: Mitigation requires replacing aging, combined sewer-stormwater networks with segregated lines. Water companies are increasingly investing in Sustainable Drainage Systems (SuDS) like rain gardens, green roofs, and attenuation ponds to capture rainwater before it overloads wastewater treatment plants.
Regulatory Compliance & Transparency: Water companies are legally required to publish Pollution Incident Reduction Plans (PIRPs), detailing their timelines and infrastructure budgets for eliminating harmful discharges and meeting government reduction targets by 2030.
At-Source Waste Management: Community-level mitigation involves preventing wet wipes (especially those containing plastics), fats, and oils from entering the sewer network to reduce blockages that trigger emergency overflows.
Nature-Based Filtration: Constructed wetlands and reed beds are being adopted to naturally filter treated wastewater, reducing nutrient (phosphorus/nitrogen) runoff before it triggers severe algal blooms.

source: google.com

II. Municipal Drinking Water Supply Contamination

If your water supply has been contaminated by sewage, immediately switch to bottled water. Do not consume, cook with, or wash with the water.

To recover safe water quality, you must either rely on the municipal supply being purged and treated, or, if using a private source like a well, shock chlorinate it and install a multi-stage filtration system.

Because restoring potable quality depends on whether the water comes from a municipal network or a private well, different recovery strategies are required:

If you are connected to the mains water network (e.g., in the UK) and a sewage backflow or contamination event occurs, the primary responsibility for water quality lies with your regional water utility.

Report the Issue: Contact your water company (e.g., Southern Water for the ME7 area) immediately. They are required to investigate.

Follow "Boil Water" Notices: If a boil water notice is issued, boil all water aggressively for at least one full minute and let it cool before using it for drinking, brushing teeth, or washing food.

Flushing the System: Once the utility declares the supply clear, you must flush your household pipes to clear stagnant, contaminated water. Open all cold-water taps (indoors and outdoors) and run them at full flow for 5–10 minutes to purge the house lines.

Water quality tablets: —often called water purification tablets—are chemical treatments used to kill harmful bacteria, viruses, and protozoa in untreated drinking water. They are lightweight, require no power, and are ideal for emergencies, hiking, and travel.

Here is a breakdown of the most common types and how they work:

i. Chlorine Dioxide Tablets

These are the most effective overall chemical treatments. They kill bacteria, viruses, and tough parasites like Giardia and Cryptosporidium.

Wait time: 30 minutes for most bacteria and viruses, but up to 4 hours for full cryptosporidium protection.
Pros: Leaves a less noticeable taste than regular chlorine tablets.

ii. Chlorine Tablets (NaDCC)

Tablets like Aquatabs or Oasis use Sodium Dichloroisocyanurate (NaDCC) and are the global gold standard for emergency relief.

Wait time: 30 minutes.
Pros: Highly effective at killing bacteria and viruses, and neutralizing water for washing produce or brushing teeth.
Cons: Generally not effective against Cryptosporidium and may leave a mild chlorine taste.

Multi-Stage Filtration Process

In a water quality emergency, prioritize a multi-stage treatment process: first remove sediment by letting heavy particles settle or straining through cloth, then filter with a 0.1-micron membrane, and finally disinfect using heat (boiling) or chemicals to neutralize viruses and bacteria.

i. Ready-Made Portable Filters (The Gold Standard)

For immediate, safe drinking water, nothing beats a dedicated, survival-grade portable filter. They handle both physical filtration and pathogen removal (bacteria and protozoa), and are highly recommended to have on hand.

Sawyer Squeeze System: This 0.1-micron hollow-fiber filter removes 99.99999% of bacteria and protozoa, screws onto standard water bottles, and lasts up to 100,000 gallons. Explore deals at Amazon UK or outdoor retailers.
Membrane Solutions Straw: A triple-NSF certified 5-stage personal straw that fits onto 28mm bottles and instantly removes 99.9999% of coliforms.
Grayl GeoPress: A premium "press-and-drink" bottle that clarifies water and eliminates viruses, heavy metals, and chemicals.

ii. The Makeshift Field Filter (If you don't have gear)

If you lack a commercial filter, you can build a layered gravity-fed system in a plastic bottle or wide tube to remove sediment, debris, and some chemicals. Layer these from bottom to top (water flows down):

Fine Material: A tight paper towel, cotton cloth, or coffee filter.
Activated Charcoal/Carbon: Crushed up campfire charcoal removes odors and impurities.
Sand: A 1 to 2-inch layer of dry, washed sand.
Gravel: Small, clean stones at the top to block large leaves and debris. [1, 2, 3, 4, 5]

Note: Makeshift filters clarify water but will not catch all viruses or small bacteria. You must disinfect the resulting water.

3. Final Disinfection (Crucial Step)

Physical filtration alone rarely kills viruses and small pathogens. Always finish with one of these steps:

Boiling: The most reliable method. Bring water to a rolling boil for 1 minute (or 3 minutes if you are above 2,000 meters/6,500 feet).
Chemical Treatment: Use chlorine dioxide tablets (like Katadyn Micropur) or unscented household bleach (5-6% sodium hypochlorite). Add 2 drops of bleach per liter of clear water, or 4 drops for cloudy water, and wait 30 minutes.

Summary Considerations