How to restore a failing septic drain field.

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Gravity fed septic tank and septic drainfield

Failing Drain Field

Whether you are seeing puddles in your backyard, or a septic tank pumper told you to replace your drainfield, don't give up hope, a cure may be close at hand.

The best way to figure out what to do about your failing drainfield is to educate yourself.

This page is a little long but if you read it through I believe you will have a reasonable understanding of what may be going on with your drainfield and learn how to treat it without digging up your yard.

Combo Shock Treatment

How To Recognize Drain field and Leach field septic system problems

Septic systems can vary in design but they all rely on the ability of the drainfield soil to absorb water. On this page drainfield, drain field and leach field are used interchangeably. All these terms refer to the same part of the septic system. Please don’t be confused.

There are many potential causes for septic system failure. When trying to diagnose a septic system problem it helps to know what to look for.  Ninety percent of septic system problems originate in the drainfield or leach field where sewage is absorbed and treated by the drainfield soil. So, that is a good place to start diagnosing your septic problem.

If you are not familiar with how a septic system works see septic system basics.

    Septic odors in the backyard near the septic tank or drainfield. 

When the leach field or drainfield floods beneficial bacteria colonies that normally keep the bio mat balanced die off.  As a result the bio mat grows thick and impermeable preventing sewage from reaching the treatment soil area. Dying bacteria colonies produce sulfites, which in turn give off an unpleasant odor.

    Household drains running slowly – sluggish field

An early sign of problems, slow running drains can indicate that the drainfield is not accepting water at a normal rate. This condition should be treated before it becomes full blown drainfield failure.

    Back-ups into low lying household drains

This is the result of not paying attention to the early signs of drainfield failure.  Once the condition of the drainfield has reached this point it is considered to be failing and needs immediate attention.

    Puddles in the backyard over the drainfield or septic tank

Puddles over the drainfield are another sign of advanced drainfield failure. Wastewater enters the drainfield at the beginning right after the D-box. As the drainage soil begins to fail or not absorb water, the wastewater will move to the next spot in the field where it can be absorbed. This process continues until the wastewater reaches the end of the drainfield and surfaces.  A puddle at the end of the drainfield is a sign of total failure.

    Septic tank service personnel observe water returning to the septic tank after pumping.

If wastewater is not being absorbed in the drainfield it will run back to the septic tank when the tank is emptied.





    Look for areas where field has been driven over

Drain pipes can be broken and gravel-filled  trenches can become compressed limiting their ability to absorb wastewater.  If possible, never build a drainfield under a driveway, pathway or road.

    Observe use habits

Grease and food put down drain causes contamination of drain field soil and overgrowth of the bio mat. 

Overuse causing soil hydraulic overload – systems are designed to handle normal amounts of water use. Extra people in the household, several laundry loads in succession and leaking faucets and toilets can lead to hydraulic overload and septic system failure.

    Determine last pump out date

Septic tanks should be pumped every 2 to 5 years depending on use. Failure to pump on a regular basis can cause drain field failure from contamination by grease and solids that should remain in the septic tank until pumped.

    Observe plants growing near and around field

Root intrusion can clog drain pipes and compromise the field.

    Determine what type of soil is native to the area

Clay in native topsoil or in layers below the surface causes hardpan

Hardpan is an impermeable layer of soil that limits the ability of drain field soil to absorb water.

    Look for a high local water table

When there has been an excessive amount of rain, or if you live near a lake or river or near the beach, there could be a high local water table in your area.  This could be a seasonal problem or it could be a poorly designed septic system that needs to be raised. In either case when the water table is high it can easily flood low-lying septic system drain fields.


    Determine the condition of your drainfield and fix it

NORMAL working septic system has none of the symptoms previously mentioned but that doesn’t mean it can be overlooked. Maintenance to keep your septic system and leach field healthy is a must.

    Our Recommendation

Have your tank pumped every 2-5 years

Keep food particles, cooking oil, grease and chemicals out of household drains

Do not use low-grade bacteria products in the septic tank as these may allow partially treated solids that should remain in the tank until removed by pumping to migrate to the drainfield soil thereby contaminating the soil and adding to the bio mat.

USE SEPTIC PERC ® – flush one gallon of SEPTIC PERC ® down a drain or toilet once every six months to keep drainfield soil from turning to hardpan, especially in areas where high amounts of clay can be found in the soil.

    SLUGGISH septic system drainfield


Possible Cause:

Grease and sludge in the drainfield causing the bio mat to accelerate in growth and block the passage of wastewater to the treatment area of the drainfield.

Treat with an 8 ounce application of MEGA BIO applied directly to the drainfield through a D-box or vent pipe.

Root intrusion blocking drainpipe holes and soil passages

Use a foaming root remover, which can be obtained at home improvement stores.

Hardpan Soil is the result of sodium contained in wastewater entering the drainfield reacting with clay particles to form an impenetrable barrier and slowing drainage. This condition cannot be helped by the application of septic system bacteria products of any kind.

    Our Recommendation:  Three gallons of SEPTIC PERC eco-friendly drainfield treatment applied through a toilet or drain. Start with one gallon followed by two more weekly 1 gallon applications.


You will know when your drainfield has failed, whether it’s the odor or the puddle in the backyard you will have a pretty good idea there’s trouble brewing.

Once you have verified that the problem is not caused by broken pipes or root intrusion or a solid blockage

WE RECOMMEND: The SEPTIC PERC ® & MEGA BIO Combo Shock Treatment – 4 gallons of SEPTIC PERC & 8 ounces of MEGA BIO.  

In extreme cases of drain field failure we recommend asking your septic system technician about Hydro Jetting your system before applying our products. This high pressure water treatment can loosen hardened sludge inside of drainage pipes increasing the chances for recovery.












Signs of septic drainfield failure

How To Determine the Cause of Drainfield Failure

How to treat septic system drainfield problems

Septic system shock treatment
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Restoring Drainfields with a Combo SHOCK Treatment

Failed drain fields may be restored by applying Septic Perc and Mega Bio as a combination SHOCK treatment.


Apply 4 gallons of Septic Perc directly to the drain field soil through a distribution box, cleanout, or el leading directly to the drain field, bypassing the septic tank. Flush it into the field with clear water from a garden hose.


Mix one 8 ounce bag of Mega Bio with 4-5 gallons of warm water and apply it in the same manner as the Septic Perc. Using a garden hose, apply enough fresh water to push the products deep into the field, usually 20 – 50 gallons.


Have the tank pumped the day you intend to apply the Combo SHOCK treatment. Standing water should be pumped from the drain field if possible to relieve backpressure. You don’t want the chemicals meant to treat the drainfield to wash back into the septic tank. You may have to dig below the surface of the soil to find your distribution box. If you do not have, or cannot find, a distribution box, cleanout, or el leading directly to the drain field, the products may be applied through the outlet of the septic tank using a funnel with a length of old garden hose attached. Place the end of the hose in the septic tank outlet and pour all 4 gallons through the funnel. Then mix 8 ounces of Mega Bio and apply it right after the Septic Perc. Follow the application with enough clear water (up to 50 gallons) to flush the product deeper into the field.


WARNING: Septic tanks can be hazardous. Noxious gases collect in the top of the tank, and tank contents pose a health hazard. We recommend hiring a licensed professional septic service technician if application must be done through the tank outlet.


PLEASE NOTE: Some septic tanks have a “T” outlet, or baffle installed on the outlet to reduce the amount of solids flowing to the drain field. These types of systems may prevent accessing the outlet in this way. If it is not possible to access the tank outlet, or use any other method of direct drain field application the product may be applied through a toilet or drain. Although not AS effective as a shock treatment applied directly to the soil, application in this manner will help restore drain field soil. Septic Perc has been shown to be effective in solutions as dilute as 1 part per 1,000.


It is the end user’s responsibility to conform to all local rules and regulations pertaining to the use of this product.

We want you to know the truth.

We don’t claim that Septic Perc and Mega Bio will solve everyone's septic system problems. We do know that years of research have developed a product that works at least as well as calcium polysulfide products with little or none of the downside, that is: no bad odor, no caustic PH and no waiting time between applications of our 2 products.

West Wind Marketing has been selling calcium polysulfide septic system treatment on the Internet since 1999. We know through customer research that such products work at least 80% of the time to restore percolation to drain field soil. When followed by a treatment using a high-grade bacteria product like Mega Bio the percentage increases to about 90%.

The bottom line is: if your septic system drain field or leach field is failing, you have several septic solutions you can try ranging from an expensive total replacement to trying a product like ours. It may not work, but it probably will, isn’t it worth a try?

We want you to be satisfied with your purchase. Before ordering make sure your plumbing is intact, and that there is no root intrusion. If you're having a problem with your system, check out the possibilities. Once you are sure that the cause of your problem is soil failure order our products.

For the best chance at restoring a failed septic drain field WITHOUT DIGGING, try our Combo SHOCK Treatment; A two-pronged attack on failing drainfield and leachfield soil. The best septic SHOCK treatment available is Eco-friendly SEPTIC PERC ® & Industrial-strength MEGA BIO.

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