Aerobic Septic System Maintenance

ATU Maintenance Tasks
ATU Maintenance Schedule
How to use liquid bleach disinfectant in an ATU
Drainfield life extension using an ATU

Summary of Maintenance Requirements for Aerobic Septic Systems

How to Care for An ATU

You can reduce problems with your ATU and extend the system life by performing basic maintenance. Also see ATU Suppliers.

Homeowners can reduce the operating cost of any septic system by conserving water use.

An aerobic system retrofit may also extend the life of a drainfield - but be sure to read the caveats described in the next section on using an ATU to extend drainfield life.

• Disinfection of septic effluent:
  
  use the proper disinfection tablets and use them on the schedule recommended by your system designer.
  
  Disinfectants are discussed just above. Typically the disinfection\ tablets are added to the system through a PVC pipe that extends above ground level and which has a removable cap. Depending on the design of your system, several tablets may be placed into a tube located inside this pipe.
  
  Don't put in more tablets than the instructions say, since doing so may cause them to break down prematurely and thus not to be dispensed at the proper rate - you'll actually end up wasting tablets and money. Check the condition of your aerobic septic system disinfection tablets monthly.


• Proper Disinfection Tablets
  
  Use only the proper type of aerobic or aeration septic system disinfection tablets in order to avoid contaminating the environment (the system may discharge insufficiently treated septic effluent and thus pathogens into the soil and groundwater) and to avoid violation of federal law.
  
  See AEROBIC Septic System Disinfection with Calcium Hypochlorite
  
  and AEROBIC Septic System Disinfection with Chlorine Tablets for details.
  
  OR
• Proper Disinfection using Household Bleach
  
  illustrated at CLEARSTREAM CLC100 / A8810 CHLORINATOR INSTRUCTIONS - using household bleach and a bleach dispenser in the ATU to disinfect septic effluent as it is discharged.


• Aerobic Treatment Unit Pumps
  
  Inspect the aerobic aeration pump monthly when you're checking the disinfectant tablets. If the pump motor is making a strange noise (or worse, has stopped working) you need repair service promptly. If your aerobic system uses a timer for pump control, make sure that device is working and has power before attacking a pump that's "not working".


• Protect from Insect Damage
  
  In some areas (such as parts of Texas) insects can damage the aerator system and void your warranty. Dulworth Septic Systems in Texas recommends putting ant poison around the aerator compartment.


• Protect from Vehicle Damage
  
  Do not drive over the septic system nor any of its components - you may damage or destroy the system. Keep grass mowed to avoid blocking or jamming components or interfering with evaporation from the absorption system.


• Aerobic Treatment Maintenance Contracts
  
  Use and maintain an aerobic treatment unit maintenance service if you are not able to reliably and properly care for your system. Studies (West Virginia) demonstrated that a high failure rate for aerobic treatment systems was due to lack of proper maintenance.


• Watch out: Check the safety of the septic system access covers:
  
  to prevent someone, adult or child, from falling into the septic tank, the covers of all of the tank's access ports must be securely fixed such that they cannot be opened by children.
  
  At SEPTIC TANK ACCIDENT REPORTS we report decades of very serious events where septic system covers have not been secure.

http://www.ahc.sa.gov.au/site/page.cfm?u=815 Adelaide Hills Council, Australia

Using an Aerobic System to Extend the Life of a Drainfield

An aerobic system might be retrofitted to a conventional septic system in an attempt to extend the life of a conventional drainfield. Also, adding aeration or oxygen to a septic system may boost aerobic bacterial action in the biomat, improving the drainfield function. But it's not quite that simple.

We would look closely at any proposals to make this "improvement" to a conventional septic system. One reader wrote that their installer wanted to simply install an aerator in the original one-compartment septic tank.

Our opinion was that unless a settlement chamber or tank outlet filter were installed the result of aeration and agitation in the primary single-chamber septic tank would be to push suspended solids out into the drain field where it would be clogged quite rapidly.

While there are a number of interesting pre-packaged advanced wastewater treatment systems on the market, a web search (in 2005 and again in 2006) does not turn up much on installation, operating, or repair costs.

The manufacturers argue that each site is unique so installation costs vary. OPINION: we suspect that as with any costly but necessary product, some vendors just don't want to give the bad news up front. When we collect more explicit septic system failure and maintenance cost data we will post it at this website.

See details at AEROBIC SEPTIC SYSTEM MAINTENANCE COSTS

See also SEWAGE TREATMENT PLANTS, RESIDENTIAL

Aerobic Treatment Unit ATU Maintenance Schedule

Below we quote an adapted version of Clearstream Wastewater System Inc.s List of Aerobic Treatment Unit ATU Maintenance Requirements & Schedule, rearranged to list items in order of frequency.

Notes to the table above

• Aerobic Septic Systems Installation, Operation, & Maintenance Manuals
• [1] Clearstream ATU website, retrieved 3/21/2013, original source: http://www.clearstreamsystems.com/service.asp . The company includes this important ATU maintenance notice:
• [2] For the first two years form the date of purchase, your local installer, from whom you purchased your Clearstream System, will inspect your system on a routine basis for operational problems.
• Service on Clearstream electrical and mechanical components will be performed at no charge, if such components are found to be defective. After the termination of the guaranteed service period, your local installer will make available a service policy for a nominal fee.
• [3] Costs for ATU maintenance tasks are gleaned from reader email and a survey of septic maintenance company websites performed through September 2015.
• CLEARSTREAM AEROBIC SEPTIC SYSTEM OWNERS MANUAL [PDF] Models 500NS - 1500N Owners Manual, Parts List, Flow Diagram, Installation Instructions, Design Drawings, Specifications, Service Policy, Warranty, Clearstream Systems, retrieved 2018/03/13, original source: https://www.clearstreamsystems.com/wp-content/uploads/2017/10/N_Book.pdf
• HOOT AEROBIC SEPTIC TROUBLESHOOTING
• HOOT Septic Systems Homeowners Manual for the H-Series IPA & EPA NPDES Systems for Ohio [PDF], HOOT Systems LLC, 2885 Highway 14E, Lake Charles LA 70607 USA, Tel: 888-878-HOOT, Website: wwwhootsystems.com retrieved 2018/03/13, original source: http://www.odh.ohio.gov/~/media/ODH/ASSETS/files/eh/sts/p-hoot-npdesownman
• Hoot Models H-500-NPDES, H750-NPDES, H1000-NPDES MANUYAL - or give Hoot a call at 888 878 HOOT or see their website www.hootsystems.com
• NESC, AEROBIC TREATMENT UNITS: An Alternative Septic System [PDF]. Pipelines, Vol. 16 No. 3 2005, NESC, West Virginia University, retrieved 2018/03/13, original source: http://www.nesc.wvu.edu/pdf/WW/publications/pipline/PL_SU05.pdf
  Excerpt:
  
  Aerobic systems treat wastewater using natural processes that require oxygen. Bacteria that thrive in oxygen-rich environments break down and digest the wastewater inside the aerobic treatment unit as they are suspended in the liquid.
• Oklahoma DEQ, AEROBIC SEWAGE TREATMENT SYSTEM MANUAL [PDF], Oklahoma Department of Environmental Quality, P.O. Box 1677 Oklahoma City, OK 73101-1677 USA Tel:(405) retrieved 2018/03/13, original source: http://www.deq.state.ok.us/eclsnew/Fact%20Sheets%20ECLS/System%20Fact%20Sheets/Aerobic.pdf

See specifics at AEROBIC SEPTIC SYSTEM MAINTENANCE COSTS

and at AEROBIC ATU SEPTIC FAILURE RATES, COSTS

Also see installation and maintenance and test instructions

at AEROBIC SEPTIC ALARM SYSTEMS

Liquid Household Bleach Disinfection in Aerobic Septic Systems

Where & How do I add bleach to my Clearstream Aerobic Septic System?

My house has a Clearstream aerobic system. I was told to remove the inner piece from the round dark green part on top of the middle circle to add bleach.

Is this correct? If it is, how do I get the inner piece out, the entire dark green part moves when I try to unscrew the inner piece? Any advice would be greatly appreciated! Thank you. On 2020-05-16 by Mikeal Hammond

Reply by danjoefriedman (mod) Instructions for using liquid household bleach in the Clearstream Aerobic Septic Sytem CLC100 / A8810 Chlorinator

Mikeal

Bottom line: yes you use liquid houshold bleach in Clearstream ATU chlorinator tanks like the one we show above (the access port) and below as the CLC 100. Check the bleach level in the reservoir tank every two to four weeks, and check also after your septic system may have high usage such as before (and after) a wedding or party at your home.

Inside the ATU a liquid chlorinator disinfection device will add a metered amount of disinfectant to the outgoing effluent that is being discharged to a sprayer or other effluent disposal method.

Details:

While it is necessary to add disinfectant to some aerobic systems, just saying arbitraily "add bleach" is a bit thin and incomplete. Whether or not you use bleach depends on the type of disinfection system installed on the ATU. How much, how often?

Above I've annotated your photograph to show the chlorinator tank access port.

You will recognize that fitting (below my yellow arrow) in the illustration below where, from Clearstream's parts store) we show Clearstream's liquid bleach disinfection system described as the Clearstream ATU "Reservoir Liquid Chlorinator - Tank"

Above is the CLC 100 Clearstream tank reservoir for liquid chlorinator a8810, a8811, a8812.

Typically for a Clearstream ATU that has a disinfection system, depending on the equipment type you will use either special disinfection tablets OR household bleach (for liquid disinfections systems like the one on your ATU.

Bleach from the liquid chlorinator tank reservoir is dispersed by a chlorinator (located inside the treatment tank) such as the The CLC 100 Chlorinator from Clearstream shown below.

Take a look at the owner's manual for your Clearstream Aerobic system - you can download the pdf that we posted at

• CLEARSTREAM AEROBIC SEPTIC SYSTEM OWNER'S MANUAL [PDF] (2014) Clearstream Wastewater Systems Inc., P. O. Box 7568. Beaumont, Texas 77726-7568 Phone: (409) 755-1500 Fax: (409) 755-6500 www.clearstreamsystems.com - Alternate source for this manual is at the Virginia Health Department at https://www.vdh.virginia.gov/content/uploads/sites/20/2021/08/Owner-Operation-Installation-Manual-Design-Dwgs-DA-Operation-Install-Maint-6-22-2021.pdf
  
  This manual Includes: the Clearstream ATU Owner's Manual. Parts List. Operating Manual Flow Diagram. Installation Instructions Design Drawings And Specifications Service Policy. Limited Warranty for these Clearstream ATU models: MODEL 500NS / NCS 500 G.P.D. MODEL 500N / NC 500 G.P.D. MODEL 600N / NC 600 G.P.D. MODEL 750N / NC 750 G.P.D. MODEL 800N 800 G.P.D. MODEL 1000N 1000 G.P.D. MODEL 1500N

You'll see that there is no discussion of adding bleach in that manual. The manual simply says:

When disinfection is required before final discharge appropriate disinfection options are available.

Clearstream's own disinfiection instructions are hard to find, but at this Clearstream FAQs page we see:

The CLC 100 Chlorinator from Clearstream is designed for residential and small commercial wastewater treatment systems.

The CLC100 is available with dosing units to meet the disinfection of most wastewater treatment systems. 

Components used in the construction of the Liquid Chlorinator are designed to last for the life of your wastewater system. For more information about the CLC 100 or to order, please visit our parts site.

For CLC100 Liquid Chlorinators, use liquid bleach. For Tablet Chlorinators, use only chlorine tablets specifically designed for wastewater use (>65% Calcium Hypochlorite). Do not use pool chlorine tablets.

Other Clearstream Aerobic Septic systems use an ultraviolet light or UV disinfection system described at

• CLEARSTREAM AEROBIC SEPTIC SYSTEM UV DISINFECTION SYSTEM - ONSITE WASTEWATER EFFLUENT UV DISINFECTION DEVICE MODEL 120 UV UNIT PART #P8888 [PDF] copy provided by the University of Minnesota, - local copy saved as Clearstream-UV-Instructions.pdf
  

So we need to know the Clearstream model you've got installed, or of course you can call Clerarsteram directly. I give their telepone numbers just above.

The most detailed Clearstream septic system instructions I've found was provided as a docx file by the University of Minnesota; for legibility and ease of use I've saved it as the following free Clearstream ATU instructions PDF Download

• CLEARSTREAM AEROBIC SEPTIC SYSTEM TECHNICAL TRAINING MANUAL [PDF]

Also see these CLEARSTREAM SEPTIC SYSTEM MANUALS posted at the company's website.

Watch out: As Clearstream warns when disinfectant tablets are being used: Use only EPA-registered chlorine tablets approved for wastewater disinfection. Do not use pool chlorine tablets. (So you certainly would also not use household bleach).

Comment by Stela

@Mikeal Hammond, We have a similar Clearstream system setup.

We need to remove the whole lid from the middle tank (in your case that would be the round dark green lid in the center), by rotating it out of its grooves.

Inside, there is a pipe where you can either add disinfection tablets, or you can just dump liquid bleach down the tank.

That's what we do, it's cheaper than the tablets and contains the same disinfectants.

Moderator comments: Watch out: warnings about using the wrong type of disinfectant: Tablets versus Liquid Bleach - use what the dispenser is designed to dispense!

Watch out: I would not add liquid bleach to a tablet dispenser nor would I use tablets in a liquid bleach dispenser on an aerobic septic treatment system. Using the wrong type of disinfectant in the dispenser may result in either equipment damage (a tablet clogging a liquid dispenser) or improper levels of effluent disinfection.

The reader, Stela, has offered some information on what their practice is for adding disinfectant to their system. Although their system may be the same as yours, I have the same concerns as I stated in my previous response:

"While it is necessary to add disinfectant to some aerobic systems, just saying arbitrarily "add bleach" is a bit thin and incomplete. How much, how often?"

I would encourage you to use the contact information from the owners manual and call them for specific and accurate information.

Watch out: Also, a technical point about which you might ask for Clearstream's opinion, is that dumping liquid disinfectant into a septic system causes a very different time-distribution of disinfectant through the system than using tablets.

Liquid disinfectant is dispersed immediately through the system at its highest concentration, and is consumed promptly as wastewater flows through the Clearstream treatment tanks.

Conversely, tablets, dissolving over time, meter out disinfectant at a lower concnentration, but more-continuously, thus providing proper disinfectant levels in the system over a longer period than would a liquid.

In short, using liquid disinfectant in place of the manufacturer's recommended tablets in any aerobic septic system may cause it to work differently, possibly with less-continuous metering of disinfectant, surges of higher-concentration of disinfectant, possible harm to sewage-breakdown-bacteria in the system from that high concentration, and periods of system use that may see too-little disinfectant.