THE MAGAZINE FOR THE DRAINAGE,WATER &WASTEWATER INDUSTRIES


MAIN FEATURE


Perhaps it is important to delineatewhat ismeant by a septic tank and what is not.Themainmisunderstanding amongst those not‘in the know’is that a septic tank and a cesspit are not the same thing.A Cesspit is a sealed‘container’intowhichwastewater is discharged and stored it does not allowfluid flowout of the cesspit into the surrounding environment andmust be emptiedwhen full and not allowed to leak during the filling or emptying process.This is not a topic thatwill be discussed here. Aseptic tank however is something completely different. Septic tanks are buried storage facilities intowhichwastewater flows are directed. Once in the tanks, in simplest formsolids sink to the bottomto forma sludgewhich over timewill need to be removedwithout spillage (it is not the nicest ofmaterials).The liquid fromthe flows is allowed to pass out of the tanks after solids removal into the surrounding environment viawhat is often, if not always, termed a‘soak away’. In the past it has been possible for these flows to enter the ground untreated (or at least not specifically treated) or into nearbywater courseswhere it is suspected that therewas a belief theywould dilute and dispersewith minimal (if any) harm– not the case today! It is perhaps useful to look at the rationale behindwhy‘recent’ regulatory changes have been introduced and their implications. Whilstmost systemoperate as described above, changes in thewaywe as a populationwork and act in our daily lives has changed considerably since the advent of the standard septic tank system.The changeswe see inmodern life have in large part rendered this type of offmains sewage treatment impractical. Whilst the original septic tanks principlewas sound in its daywith little more than poo,wee and paper going into a septic tank things have changed. Previously natural biological activity took place in the tank as the bacteria in thewaste got towork and fewif any anti-bacterial productswere used in the property served.This produced small amounts of effluent thatwas of a reasonable quality for natural disposal. Today, however, consumers use vast amounts ofwater daily in the manner previouslymentioned all ofwhich are fuelledwith highly antibacterial cleaning products thatwe have all nowbeen persuaded to use to keep ourselves and our homes andwork places pristine and as germfree as possible.Apparently, dishwasher tablets have been found to be one of themost aggressive items in themix. As these anti-bacterial systems eliminate almost all bacteria fromthe septic tank input the effluent produced is not‘treated’as it oncewas and so the fluid output can be somewhat toxic. BritishWater provides tables that give guidance on flows and loads for offmains systems and a typical 4 bed detached house is based on 1,200 litres produced over a 24 hour period.This couldmean that septic tanks that do notmeet the newregulations are each producing anything up to 1,200 litres of highly polluting untreated sewage effluent that is being discharged either into the ground or an open water course, depending on the property size. Industrial operations or commercial locations that are offnetworkmay produce evenmore of course.These siteswould include, but not exclusively, locations such as pubs, restaurants, schools, shops, public buildings, campsites, caravan parks etc. So perhaps this places some degree of scope of the size of the issue that the regulations are trying address.


HAS ANYTHINGCHANGED?


In 2015, yes some five years ago, the rules relating to the permitted discharges fromseptic tanks changed, the details ofwhichwill come later.When commissioned towrite this article one believed that the ‘rule changes’must be something newthatwas to come into force in 2020.Not the case, as this author has recently found out.These rules


FOLLOW US WHERE DIFFICULTIES ARISE


There are of course problemswith this (aren’t there always!). For example,where a buried septic tank has previously discharged into a water course, unless a full biochemical examination of the outflowis undertaken it is not possible to prove if the flowis currently allowable


July 2020 | drain TRADER 5


have been around for about half a decade and yet it is onlywhen the deadline to complywith these changes has come and gone thatwe find that feware even aware of themand the requirements they bring with them. Many, if notmost, people using septic tanks have been blissfully unaware of the need to check their systems, alter themor replace them in order to complywith the‘new’regulations.Thismeans that the majority of septic tank users are apparently currently breaking the law. So, to some extentwe could end this part of the article here by saying that little has changed. Itwould seemthat evenwith a newset of rules there are still probably 1,000s if not 10s of 1000s of septic tanks (some might saymillions) around theUK that do not complywith current requirements and neverwould have by the deadline date of the regulations, 1 January 2020. Why is this?According to some in the industry this ismainly because despite the rule changes being lawfor five years, very little has been done to promote the changes required to those that use septic tanks. Presumably this is because either those in positions of influence and power think that anyonewith such a facilitywould naturally keep up with any changes to regulations as amatter of course or such rule changes have been overshadowed and virtually forgotten in thewake of othermore perhapsmore pressing circumstances (if anyone mentions the‘B’word Iwill scream!).As it is the newregulations gave a deadline of 1 January 2020 for all septic tanks to bemade compliant with the newrules. Even so, there aremany septic tanks that have beenmodified, replaced, or abandoned for newinstallations, so let us not be too down on all owners. Butmuch of this change has been because the septic tanks theywere using became unusable and so needed to be replaced or repaired andweremade so using the newregulations as the guide.


WHAT SHOULD SEPTIC TANKS COMPLYWITH?


The idea that anywastewater flows should be allowed to pass into the environment in anyway that could do harmhas of course long gone. The efforts andmonies that have beenmade over the past 25 years or more in improvingwastewater treatment plants and improving beach quality fromWaterCompany owned and run sewer network flows is testament to that, but not so forwastewater fromseptic tanks. As of 2015, the regulations, commonly known amongst those‘in the know’asGBRs orGeneral Binding Rules, septic tanks have been required to separate solids and liquids as before but thereafter the liquids are required to be passed into an area designated as a drainage fieldwhere bacteria treats the flows as they soak into the ground.They are no longer allowed to discharge into awatercourse.The drainage field also has to be located in a position that is not too close to awater course or groundwater source to ensure that no cross-contamination can occur through untreated sewage entering thewater table that might endanger the environment or persons/livestock etc. thatmay gain access to such awater source. Where there is potential for any outflowto enter the environment untreated there is a requirement for the septic tank to feed either into or be replaced by a small‘local’treatment plantwhichwill clean the flows before allowing themto pass into thewiderworld. If such a treatment plant is installed and operational then its final outputmay be passed into the localwater course for disposal.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84