onsite sanitation systems and septage...
TRANSCRIPT
Onsite Sanitation systems and ySeptage Management
18th July, 2016
Chhavi ShardaChhavi [email protected]
25.07.2016 XXX
Structure of presentation
• Sewage/ Septage Management – Centralised and DecentralisedSewage/ Septage Management Centralised and Decentralised
approach
• Containments – Typesyp
• What is Septage?
• What is Septage Management?
• Septage Management Value Chain
• Why Septage Management is an Integral part of City wide sanitation?
• Issues in Septage Management
• Way forward – Preparation of CSPs & SFDs
Water Management Team 2
Sanitation Scenario in India
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Although the number of septic tanks will grow steeply in the next few years, there is no separate policy or regulation for septage management in India at present
Options for urban sanitation and key factors determining specific requirements
Settlement
• Water resource• Housing and Population density
l / f l
• Soil• Class 1/2/3/4/5
Settlement • Formal / informal• Asset ownership
• Ground water• Topography• Density and space
• 1‐10 lakh population• Million plus• Mega cities
Size Location
Key questions:
• On‐site / off‐site• Decentralised / centralised• Reuse
System
• Which arrangements are required for management of wastewater & faecal sludge?
• How does demand for reuse influence choice of technology?
• When and where is sewerage required and viable?
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When and where is sewerage required and viable?
Key factor: Settlement
Housing and l tiFormal /Asset W tpopulation
density
f
Formal / Informal
Asset Ownership
P bli / P i
Water resource
• amount of wastewater is function of density
• availibilty of space is function of
• Tenure• Participatory
Planning• Cross subsidy
• Public / Private • Regulation and
enforcement during design and construction
• Quantity of supply per capita
• Protection of waterbodies
density• O&M
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Key factor: Location
Soil type High ground water level
d f
Topography – high altitude, steep terrain
hi h i i toperation of soakaways
rocky ground increasescosts
reduces scope forinfiltration of wastewater
Construction of sewers, septic tanks etc. is
high pumping requirements for water
sewer can be gravity drivencosts challenging
possible intrusion ofgroundwater into sewer
space limitations
Freezing of water
Groundwater pollution
high pumping requirements for mixed sewage
Freezing of water
frozen, impermeable ground during winter limits
soaking capacities
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Key factor: System
on‐site off‐sitelow density housing /
peripheral areas
off site
requires sewer system
reliable water supply
high density housing
l b l f
low water consumption
sufficient gradient to avoid pumping in sewers
availability of services to manage septage
ground conditions allow
Higher degree of skills and human resource required
ground conditions allowabsorption of wastewaterand avoid contamination of
groundwater
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Centralised Sewerage System
It collects sewage / storm water from individual buildings, houses, public areas and transports for proper treatment and disposal.
Conventional gravity sewers (deeply placed with manholes &
Suitable for large city areas with dense population and adequatewith manholes &
pumping stations)and adequate water supply
Required highly kill d
Suitable for large
High Energy
skilled manpower for planning, execution & Operation
quantities of organic wastewater flows
High Energy requirements Overall managed
by ULB’s
Tolerant towards inflow (quantity & Require sophisti-
cated or costly
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Source: Eawag(q y
quality) fluctuationcated or costly maintenance
Decentralised Systems"Decentralised" system also refers to the cluster systems to treat all of the wastewater collectively generated by many homes or an entire community.
Suitable for smaller communities and small scale operations
Very less or no energy requirements
operations
Required basic operational skills
can augmented through modular design of all components
Mostly operated & managed by communities
intolerant towards inflow (quantity & quality) fluctuation
Source: Eawagdo not require sophisticated or costly
Suitable for organic wastewater flows from 1-1,000 m3
d
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maintenanceper day
Urban Sanitation
On SiteSystem
Off ‐Site(Piped Sewer System)
SBM
Unlined StructuresLined Structures
Two pit
Pit latrineSoak PitCesspoolSeptic Tank
Two pit latrinesBio‐digester
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Septic Tank
A sedimentation tank in whichsettled sludge is partiallyt bili d b bi di ti
most frequent onsite treatment unit worldwide
stabilised by anaerobic digestion
Consists of 2 to 3 compartments
+ simple, little space required because of being underground
+ low O&M cost
+ simple, little space required because of being underground
+ low O&M cost• Septic tanks are generally d i d l f bl k t ‐ little removal of dissolved and
suspended matter (BOD removal approx. 50%)
‐ high investment cost
‐ little removal of dissolved and suspended matter (BOD removal approx. 50%)
‐ high investment cost
designed only for black water• Effluent from septic tank further needs secondary treatment
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high investment costhigh investment costneeds secondary treatment
Septic Tanks – Technical Optionstems
Single chamberedLess Efficient
ntiona
lSyst Single chambered
Septic Tank
Conven Two chambered Septic
Tank
ystems Two chambered Septic
Tank with filter
mproved
Sy
Anaerobic BaffledRea tor ith Filter/ M Effi i t
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Im Reactor with Filter/ Biodigesters
More Efficient
Septage
“Septage” is semi‐solid matter desludged from an onsite sanitation system like septictank. It has offensive odour, appearance and contains significant levels of grease, grit,hair debris and pathogenic organismshair, debris and pathogenic organisms.
“Septage Management” is the process of managing onsite sanitation systems includingseptage collection, transportation, treatment and disposal / recycle / reuse of its contents
Components of Septage
Scum floats on the top forming a layer
septage co ect o , t a spo tat o , t eat e t a d d sposa / ecyc e / euse o ts co te ts
Scum floats on the top, forming a layer of froth which contains soap, grease etc.
Effluent the semi‐treated liquid that is qrelatively free from sludge and scum.
Sludge solids which settles at the bottom f th t k
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of the tank.
Septage Management
1
7
2
7
E i f
3
46
Emptying of septage at treatment facility / sewer
6
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5 Compost application and use of treated water for agriculture purpose
What about Grey Water and Effluent?
Black water
Grey water
EffluentGrease Trap
Septic Tank
Soak
Septage Desludging
and TransportPit Transport
DWWTsSecondary Treatment
Soil Conditioning
Irrigation/ Horticulture
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Manure/ Fertilizer
Existing Septage ManagementUnplanned and Unregulated p g
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Why Septage Management is an integral part of Citywide Sanitation ?
Policy Framework‐Legal &
Environmental
WHY?Insufficient
Infrastructure/ Measures
Sanitation‐Health &
E i t MeasuresEnvironment
Resource recovery
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Impact on Health and Environment
• Organic matter, total solids, ammonium, and helminth egg concentrations in septage are typically higher by a factor of ten or a hundred compared to wastewater sludge (Montangero and Strauss, 2002)
• Improper land application of untreated septage can adversely impact surface and groundwater quality (pathogens and nutrients).
• 37.7 million people are affected by water borne diseases annually, 1.5 million children are estimated to die of diarrhea alone, 73 million working days are lost due to water borne diseases/annum
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Statutory obligations and regulationsfor Septage Management
• Water (Prevention and Control of Pollution) Act, 1974Th E i t (P t ti ) A t 1986• The Environment (Protection) Act, 1986
• The Prohibition of Employment as Manual Scavengers & their Rehabilitation Act, 2013
• Building Codes
National
• Municipal Actsp• State Water Supply and Sewerage Acts• Municipal Drainage and Sanitation By-laws• Municipality Building Rules
State
• Local Municipal By-laws• Building RegulationsCity
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Building Regulationsy
Who is responsible for Septage Management
Public Health and Sanitation is a part of the‘ i i l ibili ’ f h i i li iPublic Health and Sanitation is a part of the‘ i i l ibili ’ f h i i li i‘constitutional responsibility’ of the Municipalitiesunder the 12th Schedule of the Constitution
h
‘constitutional responsibility’ of the Municipalitiesunder the 12th Schedule of the Constitution
h(74th CAA,1992)(74th CAA,1992)
Water Management Team25.07.2016
Statutory obligations under Municipal Act
Power to close open dischargePower to close open discharge
Disconnection of Services
Work to be done only by licensed plumbers
Protection of misuse of public sewers / infrastructure through construction of roads
Grant permission to cross private land for water / sanitation connectivity
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Tariff fixation, collection
The Prohibition of Employment as Manual Scavengers & their Rehabilitation Act, 2013
HighlightsHighlights• Conversion of Insanitary latrines to sanitary latrines
within time bound manner
U f t h l i l li f l i f• Use of technological appliances for cleaning of sewers, septic tanks to eliminate manual scavenging
• Prohibition of employment as Manual Scavengers (for p y g (hazardous cleaning of a sewer or a septic tank)
• Comprehensive Rehabilitation of the Manual Scavengers within a time bound framework by the Municipalitywithin a time bound framework by the Municipality
Offences under the Act are cognizable and non‐bailableOffences under the Act are cognizable and non‐bailable
25.07.2016 M3: Sanitation Systems
Septage as a Resource
One person produces about 500 liters of Urine500 liters of Urine and 25‐50 Kg dry matter of Faecesper year (Vinnerås, 2002 Jönsson2002, Jönsson, 2004)
Urine contains 90% nitrogen 50 65%nitrogen, 50‐65% phosphorus and 50‐80% of potassium, they are very valuable for
The annual amount of human excreta of one person corresponds to the amount of
very valuable for agriculture purpose (Esrey et al., 2001)
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The annual amount of human excreta of one person corresponds to the amount of fertilizer needed to produce 250 kg of cereal, Wolgast(1997)
Fruits grown after application of Treated Septage
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S. Vishwanath, Biome
Insufficient Infrastructure / Measures
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Issues in Septage Management
ConstructionHealth and Environment (1) Construction not as per standards
(2) Lack of secondary treatment of effluent from septic tanks
(3) Grey water also allowed along with Black water in septic tanks
(1) Illegal dumping of Septage to open areas/ drains/water bodies
(2) No Treatment
Common weaknesses and threats
Black water in septic tanks(2) No Treatment
and threats
Regulation
O & M
(1) No/negligible data on number and size of septic tanks prevalent in city Regulationof septic tanks prevalent in city
(2) Lack of periodic cleaning(3) Lack of mechanization
(1) Lack or weak enforcement of regulations and bye‐laws
(2) Overlapping functions and roles
25.07.2016 SlideM3: Sanitation Systems
Septic tank Desludgers Land Fertilizers and
Collection Transport Treatment Disposal/Reuse p g
application Manure
Pit Latrine Mounted Tractors
Co –treatment atSTP
Soak pit Vacuum Trucks
ConstructedWetland
Cesspool Vacuutug/Carts
Dewatering, Composting
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Carts Composting
Septage Management: Way forward
Need to collect and compile information on current sanitation scenario to be able to identify intervention requirements to improve city wide sanitation.
Communities / households
Planning & construction
(1) Awareness campaigns
(1) Rehabilitation of existing tanks(2) Upgradation of existing tanks(3) I t t t k i t ff it
Actions identified by CSPs
(1) Awareness campaigns(2) Behaviour change(3) Community involvement(4) O&M by private / community
(3) Integrate tanks into off‐site treatment system
by CSPsincorporated with
SFDs
Regulations
O & M(1) Clear demarcation between on‐site
and off‐site systems(2) Sustainable operator model(3) SOPs
(1) Establish bye‐laws for on‐site sanitation, and septage management
(2) Enforcement of regulations(3) Establish on‐site sanitation
monitoring framework
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monitoring framework
NEXT STEPS
Water Management Team25.07.2016