Mowing Mowing Septic tank

Anonymous Poster · Apr 25, 2002

Mr.P. It is possible that horses with their high ground pressure could damage a leach field.
Patrick, Many systems include a gray water drywell to handle that part of waste disposal. My own home was equipped that way, and have seen many installed years ago. It makes sense if your ground conditions allow it, and if it is legal. Here in the Southern Tier of NY, it is not.
Typical installations here (in poor soil) involve a sand filter like you mentioned. I install several every year helping my brother. We use geo cloth on top of the sand filter to prevent any soil infiltration.

Soundguy · Apr 25, 2002

(patrickg)

Sure, anytime.

Soundguy

patrickg · Apr 25, 2002

Bill, NO sweat, friend. Not to worry. Just saying "grey water system" is a pretty wide and varied area and can evoke strong passions pro and con. I have asked the same question to a "septic guy" and was told to put the extra capacity in enlarging the main system. That is not a universally accepted idea. Luckily we have a resident expert in waste water treatment and disposal, who while disguised as a mild mannered moonlighting sound engineer (The SoundGuy) fights the never ending battle against truth, justice, and the ... oops I mean fights the never ending battle against waste treatment and disposal ignorance.

A small community about 6 miles from me recently had the same engineer who did my perk tests design an enlargement/improvement to their waste treatment facility. Their old system was overloaded and discharged raw sewage into a creek not too far upstream of the South Canadian River. Now that excess is caught and treated so well that it is nearly potable. They treat it in batches and spray the liquid on 80 acres of hay land. The land owner signed up gladly when he got the numbers on their worst case quality of discharge. He will be making a lot of hay with that free irrigation.

I am still thinking I would like to use my grey water for subsurface irrigation if it isn't too much hassle. It sort of bothers me to throw water away when it is in short supply and can be put to better use.

Patrick

Soundguy · Apr 25, 2002

From an engineering point of view.. sprayfields are great... you get the use of this huge sand filter ( earth ) and all the local flora & fauna. And as the old saying goes.. the soloution to pollution is dilution. Some feelings may differ about spray fields ( namely those living in close proximity) but as long as the monitoring wells come up clean... it is a great use for the water.

"They treat it in batches and spray the liquid on 80 acres of hay land. The land owner signed up gladly when he got the numbers on their worst case quality of discharge. He will be making a lot of hay with that free irrigation."

Sobsurface will still have the benefit of ground filtration, without as many of the harmfull effects of runnof ( if you have runnof problems / concerns in your area).

"I am still thinking I would like to use my grey water for subsurface irrigation if it isn't too much hassle. It sort of bothers me to throw water away when it is in short supply and can be put to better use."

For simple screening, try a screen angles away from the water flow. Gives you more surface area on the filter, solids will generally collect towards the top, and the system is more or less 'self cleaning' ( incoming water pushes collected material up and away, while allowing the water to filter through) (( Low flow systems will see less benefit from this feature.)) untill the element becomes completely clogged.

Soundguy

Egon · Apr 25, 2002

Septic Tanks:
Been out at the farm working and missed all the fun for the past week.
As I recall concrete is considered as having zero tensile strength. Therefore; if no rebar is used in the manufacture of the tank, the maker cannot specify a load it will take.

Egon

Soundguy · Apr 25, 2002

Actually, non-reinforced concrete, though rarely tested, will have a tensile strength of 7-10% of the ultimate compressive strength.

And no.. I've yet to see a pre-cast structure supplier that will quote -any- load spec. You are just left to calculate it based on materials and measurements, etc. Protuct liability laws are ridiculous in this country...

Soundguy

Soundguy

"As I recall concrete is considered as having zero tensile strength. Therefore; if no rebar is used in the manufacture of the tank, the maker cannot specify a load it will take."

Egon · Apr 25, 2002

That may be but for design purposes it is zero.
Egon

DavidInNH · Apr 26, 2002

They just bought the place - I think they kind of forgot that there was a septic tank out there someplace...

-david

W5FL · Apr 27, 2002

Well, this past week, I pulled a sprayer weighing about 5000# behind my M6800 weighing about 8000# and went over a 1000 gallon and a 600 gallon septic tank about 4 times. It did not crush, but I have heard stories of Concrete Trucks and Gravel trucks busting through them.

I have mowed over my septic tank with my M6800 Kubota and a slightly smaller tractor for the past 7 or 8 years without incident. I have two cows that graze on it and weigh close to 2000#, so I guess it is safe for small Kubota's. /w3tcompact/icons/smile.gif /w3tcompact/icons/smile.gif Call the guy that put it in and ask for his advise.