WATER ANDSANITATION ~ FOR HEALH.r'-ROJECT ~4 NIGH SOIL' DISPOSAL if,N&NM0 ~~ VAT N EFFLUENT R'EUSELIN Op0 rate~qd by The LDM > 4 -.. ~ponsoredS by the U. S. Agency y{4~ '4~t 44 4 1611 N. KLnt Street,.Room 1002 > 44 Arlinglon., Virginia 22209.USA!.4 .> ~ ~ ~ ~ ~ < - STeleph one: (703).243-8200 2 -,. '. '' ' ~TeieX No. 'iVUI 64552 ~~~44> '-4' ' -'-.. j Ca'le Address WASHAID22 1 2 4>~4.)''v ser -y 4.Can- Dres.4. Mc44 4 44ee .44 In>corpg ate Principal ,4 .4 Coope atin nstit ti44. 'ahcl444 4 ubco tra4tirs al- 4>4~.'~ >44,44 P re p a 4 r d fo < r , 4 ~ 4444 44lgy a S cien ce.444444;4n d usAI Ms s16n tote4igdmo44esto 2~ 4 ~ 4 1 n I44t L4St, Re btia g 1't C a 4.I i h4.44 r, Ch 1 44 .4 4..44,) 4 WATER AN~DSAN ITATION ~ FOR HEALTH PROJECT t7 .-- "'< ' Vi VEJEUIAHV& liii ~ 30 September 1982y~) -' -'44 COORDINATION AND ..Misslion Director~~'4 w4''2 INFORMATION CENTERMaseru, LESOTHO ;'>K *,, Oerated'by The' AssociaibyteI "0''M Attn: Fred Zobri~st 4 Spo'mre bythe U.S. Agen~cy for lInternational DevelopmhentL Dear Ms. Boorady: ';On behalf of the WAS Project, I am, pIea6 '6d tb provi de' -~you 4',with 10 copies of' a report, on Night' Soil, Dispc'sal ' *and'Effluent Reu-se in',Maseru, Lesotho .* This is the final report. by Dr. Dan Okun and Dr. John S161N. KenIStreet, Room 1002 Briscoe and is based on their trip to Lesotho from ~Arlington, Virginia 22209 USA ' uy1 .924oJE9-5 92y4,'" V 4Telephone: Tee2o(73(703U 2434-820045520 This' assistance :is the result' of a requesti.by the-Mission Cable Address WASHAID 'on March; 18, .1982. Th'dkr-s 4undertaken' by' the', WASH Project on,.,Api 1 26,1982by,means,of,:Oirderiof Technical .Di rection, No. 88,,!.,utho'riized by,, theUSA IID Office of Health inWashington., I you have'.any. questions ror comments .regarding the findings do recommedations4contained in this report, we will be pto "discussthem. 4) 4Sincerely,, James E.: Beve. -~ Acting Director1 WASH Proje6ct, -cc: MriS&T/H/WS ct,,-- R. Wehan Jr 4* Dr444Mc ci . 4'nI 0 1c r.rtd :P icia~ '49 r re n ei-e Cooprafi Intiftti~n aI on ;J-4 4 0 ecea~dec'4lo 4 4 -;,R *Isiks -r I 444 ,4IC ln~titute,,4-i~ersy-of 4br '4rI~~a"-a 4 4 44Hill c4 te ia o'T -4n.ttc -6068y xlei '4gner nient tation WASH FIELD REPORT NO. 55 NIGHT SOIL DISPOSAL AND EFFLUENT REUSE IN MASERU, LESOTHO Prepared for for the USAID Mission to the Kingdom of Lesotho, under Order of Technical Direction No. 88 Prepared by: Daniel A. Okun and John Briscoe September 1982 Water and Sanitation for Health Project Contract No. AID/DSF:-c-oo80, Project No. 931-1176 is sponsored by the Office of Health, Bureau for Science and Technology U.S. Agency for international Development Washington, OC 20523 TABLE OF CONTENTS Chapter Page EXECUTIVE SUMMARY ............................................. iv ACKNOWLEDGEMENTS ...... ............ ................ ......... v 1. WASTE DISPOSAL IN MASERU: EXISTING PRACTICES AND LIKELY DEVELOPMENTS . ............ ................ .............. 1 1.1 Analysis of Current Conditions ............................ 1 lii Populations with Nu Facilities................,.... 1 1.1.2 Conventional Pit Latrines .........es................. 1 1.1.3 Ventilated Improved Pit latrines.................... 2 1.1.4 Bucket Latrines.................................. 2 1.1.5 Conservdncy Tank System ............................ 6 1.1.6 Waterborne Sewerage System......................... 8 1.2 Likely Sanitation Developments in Maseru .................. 8 1.2.1 Reducing Costs of the Bucket System .................. 8 1.2.2 Improviny Conventional Pit Latrines .................. 9 1.2.3 The Ventilated Improved Pit Latrine .................. 9 1.2.4 Subsidies and Financing .............................. 9 1.2.5 A Likely Future Scenario ............................ 11 2. POTENTIAL NIGHT SOIL DISPOSAL OPTIONS ......................... 12 2.1 General Considerations .................................... 12 2.2 Available Options ...................................... .. 12 2.2.1 Burial in New Disposal Ground ........................ 13 2.2.2 Discharging into Sewers or Industrial Stabilization Ponds ............................. ...... ......... 13 2.2.3 Using Abandoned Stabilization Ponds at Hoohlos ....... 13 2.2.4 Using Abandoned doohlos Sewage Treatment Plant ....... 14 2.2.5 Aerobic Composting ................................... 14 2.2.6 Biogas Generation .................................... 15 2.2.7 Adding Night Soil to Primary Sludge at Ratjamose Sewage Treatment Plant ................... 15 3. THE RATJAMOSE SEWAGE TREATMENT PLANT .......................... 19 3.1 Overall Description ....................................... 19 3.2 Plant 'ipacity ............................................ 20 3.3 Plant Treatment Efficiency ................................ 20 -I­ Chapter Page 3.4 Detailed Description of Wastewater Treatment Plant ........ 20 3.4.1 Trickling Filters .................................... 20 3.4.2 Tertiary Gravity Filters ............................. 21 3.4.3 Chlorination ......................................... 23 3.4.4 Monitoring ........................................... 23 3 .5 Details of Sludge Handling Features ....................... 23 3.5.1 Sludge Pumping and Piping ............................ 24 3.5.2 Sludge Digestion Tanks ............................... 25 3.5.3 Sludge Drying Beds ................................... 25 3.5.4 Sludge Disposal ...................... 26 3.6 General Plant Operations .................................. 26 4. LAND APPLICATION OF WASTEWATERS ............................... 27 4 .1 Land for Treatment of Wastewaters ......................... 27 4.2 Wastewater as a Resource for Irrigation ................... 28 5. IRRIGATION USES OF WASTEWATER ................................. 29 5.1 Status of Irrigated Agriculture in Lesotho ................ 29 5.2 Rates of Irrigation ....................................... 29 5.3 Soils in the Vicinity of Sewage Treatment Plant ........... 29 5.4 Soils in Ratjamose Area ................................... 30 5.5 Wastewater Resources for Irrigation ....................... 30 5.6 Costs of Irrigation ....................................... 31 5.7 Implementation ............................................ 31 6. CONCLUSIONS ................................................... 32 6.1 Night Soil Disposal ....................................... 32 6.2 Wastewater Treatment for Effluent Reuse ................... 32 6.3 Irrigation ................................................ 33 REFERENCES ......................................................... 34 APPENDICES A. Order of Technical Direction .................................. 35 -ii­ Page B. Officials Interviewed, and People Contacted ................... 38 C. Soil Survey in the Ratjamose Area.......................... .. 40 D. Memorandum From Daniel F. Okun to Jeffry E. !iendrich,......... 44 E. Draft Terms of Reference for Preparing a Manpower Strategy in the Water and Sanitation Sector in Lesotho ............... 49 FIGURES 1. Location of Bucket Latrines ................................... 3 2. Night Soil Deposition Facility, Ratjamose Sewag, Treatment Plant .. .. ..... .............................. 16 3. Location of Night Soil Deposition Facility .................... 17 TABLES 1. Water Standards for Various Agricultural Uses .................. 28 2. Soil Types in Ratjamose Region ................................. 30 ABBREVIATIONS USED cmd - cubic meters per day lpd - liters per day ips - liters per second m - meters gpd - gallons per day .iii- - EXECUTIVE SUMMARY In response to a request from USAID/Lesotho, USAID/Washington issued Order of Technical Direction (OTD 88) authorizing the Water and Sanitation for Health (WASH) Project to provide technical a3sistance to the Government of Lesotho on the following problems: night soil cisposal and effluent reuse through crop irrigation in Maseru. A two-person WASH team was in Lesotho from July 11 to 25, 1982. Working in conjunction with the Water Branch of the Ministry of Water, Energy, and Mining and the Office of the Maseru Town Engineer of the Ministry of the Interior, the WASH team prepared this report, Night soil from bucket latrines of 30 percent of the population of Maseru is deposited in open trenches above reservoirs which are an emergency water supply for Maseru. The WASH team Vw3s instructed to assess the feasibility of alternative night soil disposal. Estimates of the capital and operating costs of the alternatives were to be developed and recommendations presented to the Ministry of the Interior. In their investigation the consultants found that an equally if not more serious public health hazard to the night soil problem was the use by some 15 percent of the population of dongas (drainage ditches) which drain into the city water source. Regerding the night soil disposal problem, it was recommended that the only viable alternative was the construction of a night soil disposal facility at the new sewage treatment plant and that all night soil be transported and disposed of there. Regarding the effluent reuse through crop irrigation, the design and per­ formance of the new Maseru treatment plant was assessed and the suitability of the effluent for crop irrigation evaluated. A number of specific improvements for the operation of the treatment plant were recommended. rhe suitability and availability of agricultural land in the vicinity of the sewage treatment plant was assessed. A pilot wastewdter reuse scheme for Maseru was deemed feasible with the condition that agricultural specialists be involved. -iv­ ACKNOWLEDGEMENTS