Safely Managed Sanitation for All Means Fecal ... - ACS Publications

Subscriber access provided by University of Florida | Smathers Libraries

Article

Safely managed sanitation for all means fecal sludge management for at least 1.8 billion people in low and middle income countries David M. Berendes, Trent A. Sumner, and Joe M. Brown Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.6b06019 • Publication Date (Web): 27 Jan 2017 Downloaded from http://pubs.acs.org on February 7, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Environmental Science & Technology is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 28

Environmental Science & Technology

1

Safely managed sanitation for all means fecal sludge management for at least 1.8 billion

2

people in low and middle income countries

3

David M. Berendes*1, Trent A. Sumner1, Joe M. Brown1

4

1

5

Georgia, USA; *corresponding author (email: [email protected]; address: 311 Ferst

6

Dr. #3368, Atlanta, GA, 30332; phone: 404-894-3317; fax: 404-894-2278)

School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta,

7 8

Abstract

9

Although global access to sanitation is increasing, safe management of fecal waste is a rapidly

10

growing challenge in low- and middle-income countries (LMICs). The goal of this study was to

11

evaluate the current need for fecal sludge management (FSM) in LMICs by region, urban/rural

12

status, and wealth. Recent Demographic and Health Survey data from 58 countries (847,685

13

surveys) were used to classify households by sanitation facility (facilities needing FSM, sewered

14

facilities, ecological sanitation/other, or no facilities). Onsite piped water infrastructure was

15

quantified to approximate need for wastewater management and downstream treatment. Over all

16

surveyed nations, 63% of households used facilities requiring FSM, totaling approximately 1.8

17

billion people. Rural areas had similar proportions of toilets requiring FSM as urban areas. FSM

18

needs scaled inversely with wealth: in the poorest quintile, households’ sanitation facilities were

19

almost 170 times more likely to require FSM (vs. sewerage) than in the richest quintile. About

20

one out of five households needing FSM had onsite piped water infrastructure, indicating

21

domestic or reticulated wastewater infrastructure may be required if lacking for safe management

22

of aqueous waste streams. FSM strategies must be included in future sanitation investment to

23

achieve safe management of fecal wastes and protect public health.

ACS Paragon Plus Environment

1


Page 2 of 28

24


2

Page 3 of 28


25

Introduction

26

While progress toward meeting the Millennium Development Goal (MDG) target for sanitation

27

fell short in 2015—an estimated 2.4 billion people still lack access to improved sanitation1—

28

significant expansion in global coverage has been achieved in the MDG era, and investment

29

continues to reduce open defecation and expand access to safer sanitation facilities. Sustainable

30

Development Goal (SDG) 6 goes further,2 explicitly recognizing the normative goal of “safely

31

managed” sanitation in addition to coverage, highlighting the importance of safe excreta disposal

32

to reduce health risks. This shift is also reflected in refinements to the “sanitation ladder”

33

approach adopted by the Joint Monitoring Program (JMP), explicitly focusing on the safe

34

management of fecal wastes to reduce downstream exposures.1

35

Wastewater management—the removal of fecal wastes through water-based transport to

36

downstream treatment and disposal (e.g. piped networks like conventional sewerage)—has been

37

practiced as the normative standard for management of fecal waste since the mid-1800’s in urban

38

areas, where population density creates economies of scale.3 Fecal sludge management (FSM)—

39

the on-site management of fecal biosolids with generally lower water content—is a challenge

40

with new visibility in the urban sanitation sector in low and middle-income countries (LMICs).4

41

The advent of fecal waste flow diagrams and sanitation mapping exercises have revealed the

42

global predominance of on-site sanitation (dry or pour-flush latrines), even in settings where high

43

population density might justify reticulated sewerage.5,6 Many sanitation facilities available to

44

both the urban and rural poor require FSM to adequately sequester fecal wastes: a delayed, rather

45

than immediate, problem. The apparent global need for FSM services may be partly attributable

46

to the metrics-driven focus on expansion of toilets to increase coverage and reduce open

47

defecation, justifiably apriority in meeting immediate sanitation needs. More latrines, however,


3


Page 4 of 28

48

leads to concentration of wastes that must be safely managed to protect public health. FSM has a

49

tendency to be forgotten during and after infrastructure is built.7,8

50

Many households in LMICs have sanitation facilities requiring FSM services7 Despite

51

FSM’s central importance to the functionality, impact, and sustainability of global sanitation

52

infrastructure, no estimate of the worldwide need for FSM services is available. An accounting

53

of how many households require FSM is an essential step in the effort to ensure sanitation

54

infrastructure and services deliver the greatest possible health impact under the SDGs. Such

55

estimates are also valuable for advocacy, targeting FSM programs, and stimulating interest in

56

developing better FSM technologies and services to meet growing needs as sanitation coverage

57

expands.

58

This study examined the worldwide prevalence of households using sanitation facilities

59

requiring FSM based on recent Demographic and Health Survey (DHS) data from 58 LMICs.

60

We assessed the types of sanitation facilities reported to be used by households by World Health

61

Organization (WHO) region, urban/rural status, and wealth quintile to quantify the current

62

prevalence of sanitation facilities requiring FSM to function safely and to understand how this

63

prevalence varies across key population segments. We also estimated the proportion of facilities

64

reportedly used by households connected to water supplies to inform future demand for

65

wastewater management. This research will contribute to quantifying inequalities in the need for

66

FSM and wastewater management in LMICs worldwide, an explicit focus of the SDGs in

67

addressing sanitation needs for the poorest of the poor.2

68 69

Methods

70

Data sources


4

Page 5 of 28


71

Data for this study were extracted for analysis from the Demographic and Health Survey (DHS)

72

program from Phase 5 (2003-2008), 6 (2008-2013), and 7 (current, 2013-2018: the most recent

73

survey was from 2015) surveys. DHS surveys are country-specific and if a country had more

74

than one survey within the Phase 5-7 period, only the most recent survey data were analyzed.

75

DHS methodology generally involves two-stage sampling: selection of enumeration

76

areas/clusters followed by selection of households.9 Household questionnaires ask about

77

numerous topics, including water and sanitation. Questions about the kind of toilet facility used

78

by the members of the household and the main source of drinking water for the household were

79

the focus of this analysis. Further, information about urban or rural location of the household and

80

wealth were obtained from each survey. Wealth indices were country-specific and based on

81

household assets and utilities, which were weighted by the DHS program using principal

82

components analysis. These index scores were then grouped into country-specific wealth

83

quintiles based on household population figures from the survey.10

84

Classification of DHS Sanitation and Drinking Water Source Questions

85

DHS questions about the sanitation facility (DHS question 109 in Phase 7 survey11) and type of

86

drinking water source (DHS question 101 in Phase 7 survey11) were used to classify households’

87

need for fecal sludge management (FSM) or wastewater management. First, households’

88

responses to the type of sanitation facility usually used were classified into four categories: 1)

89

use of facilities connected to sewerage or sewers—any response listing connection to sewered or

90

piped system (“Sewered”); 2) use of facilities that were composting toilets, associated with

91

composting facilities, “other”, or no response (“Other/EcoSan”); 3) no use of facilities (“No

92

facility”); and 4) use of facilities that retain waste onsite (latrines connected to septic tanks and

93

subsurface discharge or pits) or discharge waste onsite (latrines with surface discharge) and


5


Page 6 of 28

94

therefore must be managed onsite (“FSM needed”). Second, households’ responses to reported

95

drinking water source were grouped into 4 categories based on location and type of infrastructure

96

associated with the source: 1) drinking water sources that were piped into the household or plot

97

(“On-premises piped connections ”, though the source may not have been onsite); 2) sources that

98

were onsite, but not piped, or were present at a neighbor’s house (“Other on-

99

premises/neighbor”); 3) sources that were not listed as onsite or at a neighbor’s house (“Not on-

100

premises”); and 4) other/no response (“Other”). Responses from both of these questions allowed

101

broad categorization of households by potential need for wastewater vs. FSM based on the type

102

of sanitation facility and piped water infrastructure present. On-premises water supply, in

103

combination with sanitation facilities, was used to indicate potential current or future demand for

104

pour-flush or flush latrines using water to convey waste, and therefore higher wastewater

105

volumes and need for access to septic systems with safe discharge (low population density) or

106

sewerage (high population density).

107

The proportions of households per country in each category were calculated using

108

complex survey weighting to account for the two-stage cluster survey techniques used in the

109

DHS.9,12 Households not responding to these questions were included in the denominator to

110

ensure accurate survey weighting and population estimates (see below). Households were further

111

divided by urban/rural status and wealth quintile. Use of sanitation facilities was quantified 1)

112

among all households, (including those with no access to sanitation); and 2) among only those

113

households reporting using sanitation facilities (to better describe FSM needs among those with

114

current access to a sanitation facility).

115

Population estimation

116

The most-recent (2016) country-level population estimates from the Central Intelligence


6

Page 7 of 28


117

Agency (CIA) Factbook13 were multiplied by the weighted proportions of households in each

118

category to estimate the total population in each category.

119

Analysis Data were analyzed from 847,685 surveys from 58 countries across all six World Health

120 121

Organization (WHO) regions: 33 countries in Africa, 7 in Latin America and the Caribbean

122

(“LAC”), 6 each in Europe and Southeast Asia, and 3 each in the Eastern Mediterranean (“E.

123

Med.”) and Western Pacific (Table 1). The total estimated population across the 58 countries in

124

the analysis was 3,205,819,618, representing 44% of the global population and 54% of the

125

population residing in LMICs as defined by the United Nations.14 All analyses were conducted in

126

R version 3.2.1 using base packages, as well as the “lme4” package for mixed-effects logistic

127

regression and the “survey” package for complex survey weighting.15–18 Mixed-effects logistic

128

regression models were used to quantify the magnitude of associations between a) drinking water

129

location, b) urban/rural status, and c) wealth quintile; and the reported use of a sanitation facility

130

that required FSM to function (compared to those connected to sewerage). Random effects for

131

country of the survey, as well as enumerations areas within each country, were included in the

132

model.

133 134

Results

135

FSM requirements among surveyed nations

136

The average prevalence and total population of households that reported using different

137

categories of sanitation facilities (connected to sewerage vs. those in need of FSM vs. no facility)

138

were calculated by country. Prevalence estimates were then averaged by WHO region and across

139

all countries surveyed, with estimated populations summed (Table 1). Over all countries


7


140

surveyed, an average of 63% of all households reported using sanitation facilities in need of

141

FSM, summing to almost 1.8 billion people out of the 3.2 billion people currently living in the

142

included countries (56%). The population-level need for FSM was greatest in Africa (mean of

143

65% of households, summing to 577 million people) and Southeast Asia (mean of 61% of

144

households, summing to 816 million people), though the Western Pacific had the highest mean

145

proportion of households reporting using facilities requiring FSM (74%).

146

To assess the need for FSM among households with current access to a sanitation facility,

147

we conducted a separate analysis of the prevalence and population of households that reported

148

using facilities in need of FSM among only those that reported using a sanitation facility.

149

Overall, 81% reported using sanitation facilities needing FSM, with over half of households

150

reported using sanitation facilities that needed FSM in all regions (data not shown). The largest

151

average figures were in the Western Pacific (94%), Africa (90%), and Southeast Asia (81%),

152

followed by LAC (63%), E. Med. (56%), and Europe (60%). Notably, almost 22% (more than 1

153

billion people) of households in surveyed nations did not use a facility currently.

154

Overall, an average of about one-quarter of households (26%) reported using on-premises

155

piped connections to water sources (693 million people). Few households (< 2% on average)

156

reported using other on-premises or a neighbor’s water sources, while most (70% on average,

157

summing to over 2.3 billion) reported using an off-premises drinking water source.

158

FSM needs in urban and rural areas in surveyed countries

159

Page 8 of 28

The average proportions of households reporting using sanitation facilities needing FSM

160

were similar in urban (66%) and rural (65%) areas, though the urban population-level need was

161

lower (735 million) when compared with the rural areas (1 billion, Table 2). Among households

162

that did not report using sanitation facilities needing FSM, the majority (79%, 248 million) in


8

Page 9 of 28


163

urban areas reported using sewered facilities, while the majority (89%, 959 million) in rural areas

164

did not report using a facility. A larger average proportion reported using sanitation facilities

165

needing FSM in urban areas, compared with rural areas, in the African region (78% vs. 60%) and

166

W. Pacific region (80% vs. 73%). However, the size of the population that reported using

167

facilities in need of FSM was generally higher in rural areas than in urban areas. Over 2.5 times

168

more people reported using facilities in need of FSM compared with sewerage in urban areas

169

(735 million vs. 285 million), while over 30 times more people reported using facilities in need

170

of FSM compared with sewerage in rural areas (1 billion vs. 32 million).

171

Among only households that reported using sanitation facilities, an average of 72% in

172

urban areas and 91% in rural areas reportedly used facilities that need FSM to function (data not

173

shown). This proportion was more variable by region in urban areas (range: 30 – 86%) compared

174

with rural areas (range: 76 – 98%). The African (86%), W. Pacific (83%) and Southeast Asian

175

(67%) regions had the largest urban proportions. In contrast, rural areas of all regions, with the

176

exception of LAC, had at least 88% of households using facilities needing FSM.

177

FSM needs by wealth quintile in surveyed countries

178

While the need for FSM appeared to be unrelated to wealth quintile across all households,

179

among households that reported using sanitation facilities (thus excluding households without

180

access to sanitation facilities, the need for FSM scaled with poverty (Table 3). For example, in

181

the richest households, an average of 64%—representing 66% of households that reported using

182

sanitation facilities (data not shown)—reported using sanitation facilities needing FSM services.

183

In contrast, in the poorest households, 50%—representing 92% of households that reported using

184

sanitation facilities—reported using sanitation facilities needing FSM services. Almost 47% of

185

the poorest households did not report using a sanitation facility.


9


186

Page 10 of 28

By population, about 2.5 times more people reportedly used facilities needing FSM than

187

sewerage in the richest quintile (457 million vs. 177 million), while almost 75 times more people

188

reportedly used facilities needing FSM than sewerage in the poorest quintile (209 million vs. 2.8

189

million). Though the proportion of households that reported using facilities needing FSM in each

190

wealth quintile was generally higher in rural areas than in urban areas, the trend of increasing

191

need for FSM from richest to poorest households among households reporting using sanitation

192

facilities was consistent between rural and urban areas (data not shown).

193

FSM needs and wastewater management potential by region among surveyed nations

194

To estimate the potential for wastewater management (in contrast to FSM), reported use

195

of “on-premises piped connections” for drinking water (from measurement of the location of a

196

household’s reported drinking water source) was used as an indicator of potential preference for

197

or possibility of flush toilets (and subsequent need for additional reticulated or domestic

198

wastewater infrastructure such as sewerage or subsurface discharge of septic effluent, Table 4).

199

Overall, an average of 69% of households with on-premises, piped connections to drinking water

200

sources reported using sanitation facilities in need of FSM to function, representing over 381

201

million people (about 22% of the almost 1.8 billion in need of FSM). These population figures

202

were highest in Southeast Asia (191 million), Africa (almost 76 million), and the Western Pacific

203

(43 million). In the Western Pacific, 93% of households with onsite, piped drinking water

204

reported using sanitation facilities in need of FSM to function. Of note, almost 100 million

205

people reported using sewered sanitation facilities, but reported having a drinking water source

206

that was not on the premises.

207

Households’ wastewater management and FSM needs were further divided by urban/rural

208

areas and wealth (Table 5). About two-thirds (259 million) of the 384 million who reported using


10

Page 11 of 28


209

both on-premises piped connections for drinking water and sanitation facilities in need of FSM

210

were in urban areas. However, an average of 78% of households in rural areas with on-premises

211

piped connections for drinking water reported used sanitation facilities in need of FSM. Overall,

212

when moving down in wealth quintile in each water category, the proportion of households that

213

reported using sewered facilities decreased and the proportion reportedly not using a facility

214

increased, similar to previous observations.

215

When examining only households that reported using sanitation facilities by wealth

216

quintile and drinking water location, both drinking water location and management of the

217

sanitation facility varied with wealth. Among the richest, 128 million (21%) reported using both

218

on-premises piped connections for drinking water and sewered facilities, another 187 million

219

(31%) reported using on-premises piped connections but used sanitation facilities in need of

220

FSM (as well as 48 million reportedly using sewered facilities without on-premises piped

221

connections), and 246 million (40%) did not report on-premises piped connections and needed

222

FSM for their sanitation facilities. However, among the poorest, there was very little reported use

223

of 1) both on-premises piped connections for drinking water and sewered facilities (1 million,

224

0.5%); or 2) on-premises piped connections with sanitation facilities in need of FSM (15 million,

225

8%). Instead, the majority (180 million, 91%) lacked on-premises piped connections and needed

226

FSM for their sanitation facilities.

227

Multivariate modeling of drinking water location, household location, and wealth on FSM need

228

within surveyed nations

229

To understand the magnitude of associations between drinking water location, household

230

location (urban/rural status), wealth, and the need for FSM, mixed-effects logistic regression was

231

used to model sanitation facilities needing FSM relative to those that were sewered among


11


Page 12 of 28

232

households reporting using sanitation facilities. Nested random effects were included for the

233

country and sub-country enumeration areas of each survey. Estimates of odds of needing FSM

234

(vs. having sewerage) are presented with 95% confidence intervals for the single, multivariate

235

model in Table 6. Households that reported using on-premises piped connections for drinking

236

water were half as likely to report using a sanitation facility in need of FSM compared to those

237

with water sources that were not onsite. Households in urban areas were 90% less likely to report

238

using sanitation facilities needing FSM compared with those in rural areas. Finally, the odds of

239

reporting using a sanitation facility needing FSM increased exponentially with decreasing wealth

240

quintile (increasing relative levels of poverty). Compared with the richest households, those in

241

the next lower quintile were 2.7 times more likely to report using a sanitation facility in need of

242

FSM, while those in the poorest wealth quintile were almost 170 times more likely.

243 244 245

Discussion The goal of this study was to estimate the current global use of sanitation facilities

246

requiring fecal sludge management (FSM) to continue to function, as well as divided by region,

247

urban/rural setting, wealth, and presence or absence of on-premises piped connections for

248

drinking water (an indicator of waste stream type and potential mobility of fecal waste). Among

249

the 58 countries included in this analysis, almost 1.8 billion people (56%) reported using

250

sanitation facilities requiring FSM to function properly, with the highest needs in rural areas.

251

Among households reporting using sanitation facilities, the poorest were also most likely to use

252

facilities in need of FSM, indicating an under-recognized disparity (beyond the 47% in this

253

quintile without access to sanitation facilities) that places additional burden on poor households

254

seeking to safely manage fecal waste. Discrepancies between the prevalence of on-premises


12

Page 13 of 28


255

piped connections for drinking water and that of sewered sanitation indicate opportunities for

256

potential wastewater infrastructure expansion, distinct from FSM as it is usually understood

257

(manual or mechanical extraction, transport, and disposal of latrine waste biosolids).

258

Although previous estimates of improved sanitation categories exist1, this study is the first

259

to quantify the magnitude of the population using sanitation facilities in need of onsite FSM at a

260

global scale and to evaluate these needs by wealth equality and urban/rural status, both important

261

covariates when informing global, national, and local policy targets and service delivery

262

models.19 Further, use of on-premises piped drinking water infrastructure as a proxy for potential

263

wastewater management, in lieu of FSM, recognizes that fecal waste management strategies

264

depend on the waste stream characteristics, which may change given that rapid expansion of on-

265

premises water service may increase wastewater volumes faster than FSM service delivery can

266

adapt. The evidence in this manuscript improves the resolution of recent global estimates of

267

improved sanitation coverage by the JMP, WHO, and UNICEF1 and geographic inequalities in

268

access to improved facilities20—both of which have not quantified FSM and sewerage needs

269

separately—in preparation for monitoring the SDGs.2,21

270

Within the 58 countries with recent DHS data (2003 – 2015), almost 1.8 billion people

271

reported using sanitation facilities that require FSM—representing over 80% of the sanitation

272

facilities in LMICs. Though likely an underestimate of the true population-level need worldwide

273

due to countries excluded from this analysis, the prevalence of FSM needs vs. sewered sanitation

274

facilities underscores the discrepancy in expenses faced by non-governmental organizations,

275

local governments, and communities between these sanitation technologies. Many reasons,

276

including the almost 40-fold higher initial costs of sewerage, previous emphasis on coverage of

277

sanitation facilities, the lack of immediate need for FSM associated with installing sanitation


13


Page 14 of 28

278

infrastructure, and the unsuitability of water-based sewerage systems in certain contexts,

279

contribute to sanitation facilities that contain waste onsite being much more prevalent than those

280

connected to sewerage worldwide.22–24,6 While onsite containment may safely separate fecal

281

waste from human contact immediately after being built, the sustained functionality and usability

282

of these facilities depends on management of the sludge: a large logistical and time burden for

283

users.22,25 Access, availability, cost, and reliability of FSM emptying services are highly variable

284

worldwide, depending on a range of locally specific factors.24,26–29 In contrast to areas already

285

piped for sewerage, areas with facilities in need of FSM incur logistical, financial, and

286

governmental challenges.6,30,31 Recent studies in large cities of LMICs have indicated that

287

governmental organization of FSM is generally poor, making sustained, reliable FSM

288

difficult.6,32 With the renewed focus on safe management of fecal sludge along the entire

289

sanitation chain in the SDGs, local governments must begin to include longer-term

290

considerations of the management of fecal sludge with existing demands for growth of sanitation

291

coverage.1,2

292

The need for FSM is not restricted to urban areas, where much of the research has been

293

focused, but instead is just as prevalent in rural populations.5,6,33 In contrast to the division

294

between sewered and unsewered facilities in urban areas, households in rural areas lacked

295

sewerage (likely due to infrastructural constraints in connecting households) and thus only

296

reported using unsewered facilities, if they reported using a facility at all.23 Despite rural areas

297

having more space to dig new pits than urban areas, they face other FSM needs in the form of

298

poorer availability of knowledge, training, and resources sufficient for the user to construct a

299

new collection area (i.e. dig a new pit), safely cover the old pit, and move the superstructure.29

300

Further, in many rural areas of the world, including India, water-based sanitation is a cultural


14

Page 15 of 28


301

necessity, which therefore requires homes to have septic tanks or other onsite collection tanks,

302

increases the volume of sludge in the tanks, and necessitates conventional emptying similar to

303

urban areas.34,35 Thus, there is a need to provide for the technical aspects and logistics of facility

304

maintenance—either through separate services or in trainings to the user themselves—as part of

305

sanitation facility construction in rural areas.36

306

The costs of FSM needs are unequally distributed across the wealth spectrum due to

307

geographic inequities in infrastructure and differences in the financing and payment structures

308

between sewerage and FSM. Areas with sewerage are generally more expensive to live in, yet

309

have the benefit of wastewater management included in the cost or otherwise borne, in large part,

310

by the utility.22,29,37 In contrast, financial structures for FSM pass the majority of costs on to the

311

users themselves—up to 84% of the annual operating costs compared to 6% for sewered systems

312

in previous literature from Dakar, Senegal.22 These costs, by themselves, constitute a large

313

portion (almost 5%) of household income in the poorest neighborhoods and often are borne in

314

the form of one-time payments, rather than monthly installments.22,38 These financial concerns—

315

with the logistical burden associated with unreliable service—may force the poorest users to

316

either empty the waste themselves or abandon regular management of their sanitation facilities,

317

contaminating the local environment with fecal pathogens and increasing subsequent health

318

risks.22,25,39 In addition to their own fecal sludge, the fecal sludge of others further ‘upstream’

319

may impact the exposure of low-income households, for example in urban informal settlements,

320

with annual flooding, exacerbating health risks.40–43

321

A limitation of this study is that the need for FSM was assessed based on the standard DHS

322

sanitation metric, a self-reported measure that largely focuses on where defecation occurs, rather

323

than the final fate of the household’s fecal sludge, in the most recent DHS data available for each


15


Page 16 of 28

324

country. There is a need to develop more comprehensive, rapid, feasible, and potentially risk-

325

based assessments of sanitation facilities and FSM to measure safe containment along the entire

326

sanitation chain.44

327

Further, these data give no indication of the composition of fecal sludge biosolids, current

328

availability of FSM services, functionality of sewerage, or the final treatment of the fecal sludge

329

in either case, limiting conclusions about the overall safety of the sanitation system present or the

330

potential for unmet demand for FSM services. While on-premises piped connections were used

331

to estimate potential need for strategies addressing more aqueous wastewater streams, the finding

332

that 100 million people used sewered sanitation yet lacked on-premises water connections

333

suggests a need for further investigation. Also, it is important to note that fecal waste transported

334

by sewerage may remain untreated in its final fate in many cases, thus sewerage – like other

335

FSM strategies - does not guarantee safe sanitation that precludes downstream human

336

exposure.45 Estimates of service provision from a study of 12 cities throughout four of the six

337

WHO regions suggest that a majority of fecal waste in onsite systems is not safely managed (61-

338

72% in Africa, 62-68% in LAC, 100% in SE Asia, and 5-100% in W. Pacific, the region with the

339

most variation) and in only 1/12 cities were 100% of sewered systems considered safely

340

managed.6 These data represent selected urban areas and thus there is a need for more active

341

research in quantifying current levels of service provision, including in rural areas.

342

While the construction and maintenance costs of sanitation facilities in need of FSM may

343

be lower for the implementer and FSM systems may be more sustainable than water-based

344

sewerage in the long term, their costs need to be included in the sanitation costs associated with

345

achieving the SDGs.22 The need for FSM is growing, both with the future expansion of sanitation

346

coverage to the more than 1 billion people in surveyed nations without a facility and with the


16

Page 17 of 28


347

filling of pits and septic tanks of the almost 1.8 billion people currently served by sanitation

348

facilities in need of FSM. Further, increasing coverage of piped water infrastructure supplying

349

greater volumes of water to households will likely result in higher prevalence of water-based

350

flush toilet use. Local water provision can therefore change the nature of fecal waste streams,

351

resulting in greater volumes of more mobile waste requiring wastewater conveyance and

352

treatment. More aqueous waste may change technology choice and drive sanitation infrastructure

353

development. Given the interconnections between water and sanitation infrastructure expansion,

354

a systems approach to ensure safe management of fecal waste may be helpful to sustain both

355

human and environmental health.46

356

The current need of FSM worldwide is large and inequitably distributed amongst the

357

poorest households in both rural and urban areas. Existing piped water networks suggest that the

358

infrastructure for wastewater management may be present for about one out of every five people

359

with sanitation facilities without sewerage; however, for the rest of the population, financially-

360

sustainable and logistically-feasible business models for reliable, safe FSM services are needed.

361

In all, both wastewater management and FSM represent the next challenge in sanitation service

362

provision to ensure that the sustainable development goals are met and thus improve human

363

health and well-being.


17


364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409

Page 18 of 28

References (1) (2) (3) (4) (5)

(6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20)

(21) (22)

(23)

WHO and UNICEF. 2015 Update and MDG Assessment. 2015. United Nations. Transforming our world: The 2030 agenda for sustainable development; 2015. United Nations Centre for Human Settlements. The Design of Shallow Sewer Systems; Nairobi, 1986. Burian, S. J.; Nix, S. J.; Pitt, R. E.; Durrans, S. R. Urban Wastewater Management in the United States: Past, Present and Future. Jounal Urban Technol. 2000, 7 (3), 33–62. Peal, A.; Evans, B.; Blackett, I.; Hawkins, P.; Heymans, C. Fecal sludge management (FSM): analytical tools for assessing FSM in cities. J. Water, Sanit. Hyg. Dev. 2014, 4 (3), 371. Peal, A.; Evans, B.; Blackett, I.; Hawkins, P.; Heymans, C. Fecal Sludge Management : a comparative analysis of 12 cities. J. Water, Sanit. Hyg. Dev. 2014, 4 (4), 563–575. Koné, D. Making urban excreta and wastewater management contribute to cities ’ economic development : a paradigm shift. Water Policy 2010, 12, 602–610. Chunga, R. M.; Ensink, J. H. J.; Jenkins, M. W.; Brown, J. Adopt or adapt: Sanitation technology choices in urbanizing Malawi. PLoS One 2016, 11 (8), 1–16. ICF International. Demographic and Health Surveys Sampling and Household Listing Manual; 2012. Rutstein, S. O.; Johnson, K. The DHS Wealth Index. DHS Comp. Reports No. 6 2004, 1– 71. The Demographic and Health Survey Program; United States Agency for International Development. 2016 DHS household survey questionnaire; 2016. Vanderelst, D.; Speybroeck, N. Loading, merging and analysing demographic and health surveys using R. Int. J. Public Health 2014, 59 (2), 415–422. Central Intelligence Agency. The World Factbook: Country Comparison:: Population. United Nations. World Population 2015; New York, 2015. R Core Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing: Vienna, Austria 2015. Bates, D.; Maechler, M.; Bolker, B.; Walker, S. Fitting Linear Mixed-Effects Models Using lme4. J. Stat. Softw. 2014, 67 (1), 1–48. Lumley, T. survey: analysis of complex survey samples. 2016. Lumley, T. Analysis of complex survey samples. J. Stat. Softw. 2004, 9 (1), 1–19. Mehta, M.; Knapp, A. The Challenge of Financing Sanitation for Meeting the Millennium Development Goals for Meeting The Millennium Development; 2004. Pullan, R. L.; Freeman, M. C.; Gething, P. W.; Brooker, S. J. Geographical Inequalities in Use of Improved Drinking Water Supply and Sanitation across Sub-Saharan Africa: Mapping and Spatial Analysis of Cross-sectional Survey Data. PLoS Med. 2014, 11 (4). WHO; UNICEF. JMP green paper: global monitoring of water, sanitation and hygiene post-2015. 2015. Dodane, P.-H.; Mbéguéré, M.; Sow, O.; Strande, L. Capital and operating costs of fullscale fecal sludge management and wastewater treatment systems in Dakar, Senegal. Environ. Sci. Technol. 2012, 46 (7), 3705–3711. Fry, L. M.; Mihelcic, J. R.; Watkins, D. W. Water and nonwater-related challenges of achieving global sanitation coverage. Environ. Sci. Technol. 2008, 42 (12), 4298–4304.


18

Page 19 of 28

410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455


(24)

(25)

(26)

(27) (28) (29)

(30) (31)

(32)

(33) (34) (35) (36)

(37)

(38) (39)

(40)

Bassan, M.; Brdjanovic, D.; Dangol, B.; Dodane, P.-H.; Hooijmans, C. M.; Manuel Lopez-Vazquez, C.; Mbeguere, M.; Mikhael, G.; Moya Diaz-Aguado, B.; Niwagaba, C. B.; et al. Faecal Sludge Management; Strande, L., Ronteltap, M., Brdjanovic, D., Eds.; IWA, 2014. Jenkins, M. W.; Cumming, O.; Scott, B.; Cairncross, S. Beyond “improved” towards “safe and sustainable” urban sanitation: assessing the design, management and functionality of sanitation in poor communities of Dar es Salaam, Tanzania. J. Water, Sanit. Hyg. Dev. 2014, 4 (1), 131. Ingallinella, a M.; Sanguinetti, G.; Koottatep, T.; Montanger, A.; Strauss, M. The challenge of faecal sludge management in urban areas--strategies, regulations and treatment options. Water Sci. Technol. 2002, 46 (10), 285–294. Boot, N. L. D.; Scott, R. E. Faecal sludge in Accra, Ghana: problems of urban provision. Water Sci. Technol. 2009, 60 (3), 623–631. Oyoo, R.; Leemans, R.; Mol, A. P. J. The determination of an optimal waste management scenario for Kampala, Uganda. Waste Manag. Res. 2013, 31 (12), 1203–1216. Nelson, K. L.; Murray, A. Sanitation for Unserved Populations: Technologies, Implementation Challenges, and Opportunities. Annu. Rev. Environ. Resour. 2008, 33 (1), 119–151. Ashipala, N.; Armitage, N. P. Impediments to the adoption of alternative sewerage in South African urban informal settlements. Water Sci. Technol. 2011, 64 (9), 1781–1789. Kennedy-Walker, R.; Holderness, T.; Alderson, D.; Evans, B.; Barr, S. Network modelling for road-based faecal sludge management. Proc. Inst. Civ. Eng. Eng. 2015, 167 (ME3), 157–165. Bassan, M.; Mbéguéré, M.; Tchonda, T.; Zabsonre, F.; Strande, L. Integrated faecal sludge management scheme for the cities of Burkina Faso. J. Water, Sanit. Hyg. Dev. 2013, 3 (2), 216. Chowdry, S.; Kone, D. D. Business Analysis of Fecal Sludge Management: Emptying and Transportation Services in Africa and Asia. 2012, No. September, 116. Coffey, D.; Gupta, A.; Hathi, P.; Khurana, N.; Spears, D.; Srivastav, N.; Vyas, S. Revealed Preference for Open Defecation. Econ. Polit. Wkly. 2014, 49 (38), 43–55. Coffey, D.; Gupta, A.; Hathi, P. Culture and the health transition: Understanding sanitation behavior in rural north India; 2014. Tilley, E.; Strande, L.; Lüthi, C.; Mosler, H.-J.; Udert, K. M.; Gebauer, H.; Hering, J. G. Looking beyond Technology: An Integrated Approach to Water, Sanitation and Hygiene in Low Income Countries. Environ. Sci. Technol. 2014, 48, 9965–9970. Fobil, J.; May, J.; Kraemer, A. Assessing the relationship between socioeconomic conditions and urban environmental quality in Accra, Ghana. Int. J. Environ. Res. Public Health 2010, 7 (1), 125–145. Parkinson, J.; Boot, N. Assessing demand for faecal sludge management ( FSM ) services in Freetown. Waterlines 2016, 35 (4), 336–356. Berendes, D.; Kirby, A.; Clennon, J. A.; Raj, S.; Yakubu, H.; Leon, J.; Robb, K.; Kartikeyan, A.; Hemavathy, P.; Gunasekaran, A.; et al. The Influence of Household- and Community-Level Sanitation and Fecal Sludge Management on Urban Fecal Contamination in Households and Drains and Enteric Infection in Children. Am. J. Trop. Med. Hyg. Accepted. Kolsky, P. J.; Butler, D. Solids size distribution and transport capacity in an Indian drain.


19


456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476

(41)

(42) (43)

(44)

(45)

(46)

Page 20 of 28

Urban Water 2000, 2 (2000), 357–362. Turley, R.; Saith, R.; Bhan, N.; Rehfuess, E.; Carter, B. Slum upgrading strategies involving physical environment and infrastructure interventions and their effects on health and socio-economic outcomes (Review); 2013. Unger, A.; Riley, L. W. Slum health: From understanding to action. PLoS Med. 2007, 4 (10), 1561–1566. Berendes, D.; Leon, J.; Kirby, A.; Clennon, J.; Raj, S.; Yakubu, H.; Robb, K.; Kartikeyan, A.; Hemavathy, P.; Gunasekaran, A.; et al. Risk factors for pediatric enteric infection in a low-income urban neighborhood in Vellore, India: Examining the contributions of the household environment, neighborhood geography, and exposure behaviors. In Water and Health Conference: Where Science Meets Policy; 2016. Acker, W.; Parkinson, J.; Mabote, M.; Campos, L. C. Assessing health risks associated with municipal sanitation systems in Maputo, Mozambique. Waterlines 2016, 35 (4), 397– 411. Baum, R.; Luh, J.; Bartram, J. Sanitation: A global estimate of sewerage connections without treatment and the resulting impact on MDG progress. Environ. Sci. Technol. 2013, 47 (4), 1994–2000. Zuerbruegg, C.; Tilley, E. A system perspective in sanitation – Human waste from cradle to grave and reincarnation. Desalination 2010, 251 (May 2008), 410–417.

477


20

Page 21 of 28


Table 1: Sanitation coverage and location of drinking water source by country and WHO region among surveyed nations Sanitation coverage and type Sewered FSM needed No facility On-premises piped

All countries (n = 58) Africa (n = 33) Angola Benin Burkina Faso Burundi Cameroon Chad Comoros Dem. Rep. Congo (DRC) Rep. Congo Cote d’Ivoire Ethiopia Gabon The Gambia Ghana Guinea Kenya Lesotho Liberia Madagascar Malawi Mali Mozambique Namibia Niger Nigeria Rwanda Sao Tome and Principe Sierra Leone Tanzania Togo Uganda Zambia Zimbabwe LAC3 (n = 7) Bolivia Colombia Dominican Rep. Guyana

Location of drinking water connection Other onNot on-premises premises/neighbor Total pop.2 Mean %1 Total pop.2 Mean %1 Total pop.2 693,404,785 1.9 146,891,193 70.1 2,348,469,785

Mean %1 14.0

Total pop.2 316,555,344

Mean %1 62.8

Total pop.2 1,774,646,390

Mean %1 21.6

Total pop.2 1,073,001,372

Mean %1 26.3

5.4 7.6 1.3 0.6 1.1 0.8 0.9 5.3 0.2

30,861,856 1,528,842 143,235 114,192 119,586 202,626 102,381 42,351 173,509

65.4 13.2 43.5 50.1 95.9 92.0 28.1 92.4 85.0

577,391,250 2,660,805 4,673,442 9,779,179 10,642,929 22,413,865 3,327,184 733,944 69,136,238

27.5 40.7 54.2 49.0 3.0 7.0 71.0 0.8 14.7

225,737,951 8,208,601 5,823,062 9,567,314 336,784 1,716,622 8,415,066 6,440 11,965,843

17.9 12.7 19.9 13.1 5.1 14.7 5.6 37.9 15.2

96,256,978 2,560,256 2,142,270 2,556,771 564,626 3,585,025 659,492 301,257 12,362,962

0.7 0 0 0 1.8 0 0 0 0

8,640,317 0 0 0 203,615 0 0 0 0

81.4 87.3 80.1 86.9 93.1 85.3 94.3 62.0 84.8

742,524,581 17,612,076 8,599,188 16,954,326 10,329,652 20,769,262 11,172,449 492,167 68,951,625

1.6 6.4 0.6 33.2 2.6 7.8 3.0 10.0 1.4 1.0 0.2 3.5 1.5 0 37.3 0.6 5.5 1.3 5.8

78,910 1,523,470 595,967 577,528 51,282 2,106,401 368,094 4,672,579 28,179 43,968 40,586 649,314 256,438 0 908,277 110,094 10,158,331 165,596 11,391

89.6 60.1 56.4 63.5 95.2 75.2 77.4 81.6 71.4 53.5 43.3 84.2 87.3 58.3 16.0 26.6 65.0 94.0 32.3

4,347,436 14,256,340 57,709,987 1,103,764 1,913,845 20,245,354 9,363,303 38,164,707 1,395,101 2,299,195 10,570,207 15,627,166 15,251,150 15,122,858 389,366 4,949,480 120,960,291 12,206,930 63,850

8.7 33.2 38.3 2.3 2.1 16.9 19.5 8.0 27.1 45.2 56.5 12.2 11.0 41.7 46.3 72.8 29.4 3.9 61.4

421,091 7,892,666 39,230,191 40,217 42,219 4,544,237 2,354,183 3,753,824 529,666 1,942,180 13,798,349 2,267,951 1,924,261 10,807,292 1,127,743 13,566,790 54,741,717 507,909 121,321

25.4 31.5 11.0 63.7 41.5 9.7 22.2 24.2 25.6 1.1 2.8 14.2 8.9 10.8 50.9 7.2 2.8 9.5 30.6

1,231,022 7,471,807 11,273,281 1,108,172 834,865 2,616,601 2,685,567 11,330,076 499,662 46,044 693,069 2,644,986 1,555,712 2,806,116 1,241,232 1,337,438 5,175,068 1,229,950 60,370

0 0 0 0.4 0 0 0 0 0 0 0 0 0 6.3 0 0 0 0 0

0 0 0 6,247 0 0 0 0 0 0 0 0 0 1,641,587 0 0 0 0 0

74.6 68.4 88.9 35.7 58.4 90.3 77.7 75.8 74.4 98.8 97.2 85.8 91.1 82.8 49.0 92.8 97.0 90.5 69.4

3,619,567 16,246,299 91,061,315 620,575 1,172,910 24,291,661 9,402,358 35,460,682 1,453,408 4,250,152 23,737,256 15,925,335 15,911,396 21,482,447 1,192,663 17,301,162 180,531,398 11,753,375 137,171

0.2 0.7 0.1 0.6 10.2 26.8

14,249 348,081 4,120 244,695 1,581,279 3,896,307

77.8 86.6 50.3 93.4 73.5 46.9

4,684,981 45,471,705 3,900,354 35,794,731 11,407,105 6,824,457

21.4 12.3 48.8 5.7 16.2 26.2

1,286,522 6,474,557 3,786,204 2,199,710 2,519,829 3,817,593

3.6 10.8 5.7 6.2 18.1 28.8

218,404 5,658,961 438,616 2,368,910 2,812,463 4,185,926

0 12.6 0 0.5 0 0

0 6,606,672 0 182,196 0 0

96.2 76.6 94.3 93.3 81.7 71.2

5,790,009 40,217,093 7,311,512 3,574,177 12,671,430 10,361,035

31.3 75.0 72.9 4.2

46,342,876 35,415,596 7,731,733 30,981

55.1 20.1 23.7 94.7

44,666,150 9,508,821 2,509,509 697,212

10.0 4.8 3.4 1.0

11,189,454 2,267,916 363,569 7,451

48.5 78.7 83.9 10.6 32.4

78,346,621 8,636,131 39,621,592 1,128,415 238,352

0.5 0 0 0 0

768,541 0 0 0 0

50.9 20.9 16.1 89.4 67.6

40,482,594 2,293,483 7,599,264 9,478,229 497,389


21


Page 22 of 28

Haiti Honduras Peru

1.0 34.4 0

108,934 3,055,625 0

73.6 55.9 62.7

7,715,094 4,971,207 19,264,308

25.1 9.4 16.5

2,632,616 834,991 5,082,912

8.6 48.6 76.4

906,134 4,317,778 23,498,159

1.7 0 1.9

174,493 0 594,048

89.6 51.4 21.6

9,391,107 4,574,265 6,648,856

E. Med. (n = 3) Jordan Pakistan Yemen

38.2 60.3 29.6 24.5

71,535,375 4,938,352 59,877,818 6,719,204

46.1 39.7 49.0 49.8

115,771,012 3,245,787 98,880,200 13,645,025

15.5

Safely Managed Sanitation for All Means Fecal ... - ACS Publications

Recommend Documents