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Septic Tank Condition - How to Inspect Steel Septic Tanks InspectAPedia®  -     Characteristics of steel septic tanks Types of Septic Tanks: steel septic tanks, concrete septic tanks, fiberglass septic tanks, home made septic tanks - definitions and characteristics of various types of septic tanks

This document describes how to inspect the condition of a septic tank, providing special considerations for inspecting steel septic tanks. Inspecting steel septic tanks is a key component in onsite wastewater disposal systems. The photo shows an area where the author walked just before stepping through a rusted-out steel septic tank cover (shown below).

This is a chapter of Septic Systems Inspection, Testing our online book about septic system inspection procedures, defects in onsite waste disposal systems, septic tank problems, septic drainfield problems, checklists of system components and things to ask. Also see The Septic Information Website our main page of articles and information about septic systems and onsite wastewater disposal systems inspection, testing, diagnosis, maintenance, and repair.

© Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

STEEL SEPTIC TANKS - Life Expectancy, What Breaks, What to Look For

Steel septic tanks typically last 20-25 years, then rust, and collapse. Before this time steel baffles may rust off (damaging the drain field with sludge), the tank top may become rusty and unsafe, or the tank bottom may have rusted through. You can see the steel septic tank baffle in the lower left of this photo - notice that the top edges of the baffle have rusted away? In the photo shown here the steel septic tank cover had rusted through and was covered with brush and about two inches of soil.

Guide to Steel Septic Tank Maintenance and Repair

Keep surface and roof runoff away from steel septic tanks or any other septic tanks and also from other septic system components like D-boxes and drainfields. Flooding the system with uninvited water risks shortening the drainfield life and leads to septic system failure. In the photo at left the steel septic tank is not only located too close to the house (typical for the era of its installation in the 1960's), but also it is near a roof drainage downspout. The owner has wisely added an extension to redirect downspout spillage away from this tank.

Special Hazard Warning for Steel Septic Tank Covers

Rusting steel tank covers can cause death! Rusted covers can collapse. We have reports of children and adults who have died from this hazard, as recently as December 1997. In 2000 the author consulted in a fatality involving an adult falling into a cesspool.

At a building inspection the author, even though walking carefully, stepped through a hidden, rusted-through steel septic tank cover (shown in the photo included here).

Falling into a septic tank, drywell, or cesspool is quickly fatal, either from being buried by falling soils and debris, or by asphyxiation. Septic gases are highly toxic and can kill in just minutes of exposure. Even leaning over an empty (just pumped) tank has led to collapse and fatality of a septic pumper.

Steel septic tank baffle problems: on a steel septic tank the inlet and outlet baffles often rust out and fall off before the owner realizes that the tank needs repair or replacement. This damage permits solids to enter the soil absorption system. In the photo shown above on this page the steel septic tank baffle has rusted away at its top - visible in the lower left of the tank top opening. If a steel septic tank is otherwise in good condition but its baffles have become damaged or have been lost entirely, try inserting a plastic tee in the inlet and outlet waste lines.

Septic tank baffles, or septic tank tees prevent solids from flowing out of the tank into the drainfield, or from blocking waste flow into the tank from the building it serves. But if you see that the steel septic tank baffles have been missing for some unknown time, perhaps a long time, especially at the tank outlet end, you can assume that this condition has reduced the future life of the drainfield by permitting solid waste to flow into that area of the septic system. See Septic Tank Tees for more details about this septic system component.

Steel tank bottoms rust out permitting effluent to leak into soils around the tank, possibly giving a large void in tank at time of testing, thus subverting a loading or dye test. Since steel tank tops can be replaced while leaving the old tank in place, the condition of the top itself is not a reliable indicator of tank condition.

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Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

INSPECTING SEPTIC TANKS
  SEPTIC TANK INSPECTION CHECLIST
  STEEL SEPTIC TANKS
  CONCRETE SEPTIC TANKS
  FIBERGLASS / PLASTIC SEPTIC TANKS
  HOME MADE SITE BUILT TANKS
  SEPTIC TANK BAFFLES
  SEPTIC TANK SOLIDS & SCUM

More Reading about septic tanks

• Septic Tank Location - How to Find the Septic Tank
• INSPECTING SEPTIC TANKS - how to inspect septic tanks, a checklist, and the proper sequence of inspection during septic tank pumping
• MEASURE Septic Tank SCUM & SLUDGE - How and Why to Measure Septic Tank Scum and Sludge in the Septic Tank
• Septic Tank EFFLUENT RETENTION TIME - Septic Effluent Retention time and Effective Septic Tank Volume - Why pump a septic tank before it is "full" of solids and grease?

The Septic Systems Online Book - Where Are We?

More Information on Building Diagnostic Inspections and Repairs

• Inspecting Septic Systems: Inspection, Test, Diagnosis, Repair, & Maintenance: Our Online Septic Book: Septic Testing, Loading & Dye Tests, Septic Tank Pumping, Clearances, details of onsite waste disposal system inspection, testing, repair procedures.
• Tank Location - How to Find the Septic Tank, how deep will the cover be, how to document its location
• Septic Tank Pumping Frequency Table
• The Septic System Information Website - Extensive, Detailed Consumer and Industry Information on Septic System Inspection, Testing, Maintenance, Alternatives for on-site waste disposal
• Alternative & Advanced Designs for Septic Systems for discussion and links to (on-site waste disposal) System Designs for Problem Sites & Soils. Books, Consultants, Engineers, Designers. Alternative septic system designs can substantially reduce the normal required distances between septic system components and wells, lakes, streams, and property boundaries.

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