Initial Environmental ExaminationLinked Document 13 South Tarawa Sanitation Improvement Sector Project (RRP KIR 43072) INITIAL ENVIRONMENTAL EXAMINATION OF OCEAN OUTFALLS SUBPROJECT

Initial Environmental Examination June 2011

KIR: South Tarawa Sanitation Improvement Sector Project

Linked Document 13 South Tarawa Sanitation Improvement Sector Project (RRP KIR 43072)

INITIAL ENVIRONMENTAL EXAMINATION OF OCEAN OUTFALLS SUBPROJECT

I. INTRODUCTION

1. The proposed subproject will comprise the upgrading or replacement of the ocean outfalls at the urban centers of Betio, Bairiki, and Bikenibeu on South Tarawa under the South Tarawa Sanitation Improvement Sector Project. The integrity and effectiveness of the ocean outfalls is an essential part of the solution to the growing and intense problem of water pollution in the freshwater lenses below the atolls of South Tarawa and of the lagoon, as well as the serious effects on public health of poor sanitation. While the subproject presents the only feasible alternative to the amelioration of the current situation regarding the release and buildup of nutrients and pathogens, there are potential adverse impacts associated with the release of these into the ocean. This initial environmental examination (IEE) examines the potential impacts in respect of proposed subproject outputs and identifies mitigation measures to avoid adverse impacts and maximize beneficial impacts to the extent possible. The IEE was prepared according to the Asian Development Bank’s Safeguards Policy Statement, 2009 and in accordance with the Environment Act, 1999 and the Environment (Amendment) Act, 2007. 2. This IEE was prepared employing site visits, consultations, field investigations, and review of secondary sources of information relating to the subproject.

II. POLICY LEGAL AND ADMINISTRATIVE FRAMEWORK

3. Policy and law in the Republic of Kiribati are guided by the national constitution, which vests the natural resources of Kiribati in the people and the government, and affords protection to public health, the health of animals and plants, and the conservation of the environment. 4. The principal law relating to environmental protection and management is the Environment Act (1999), as amended by the Environment (Amendment) Act 2007 and supported by the Environmental (General) Regulations of 2009 (which repeals previous regulations to the act). Further relevant documents of relevance are (i) the Public Utilities Ordinance of 1977, which vests responsibility for the protection and security of water resources in the Public Utilities Board (PUB), and includes regulations for the protection of water reserves; (ii) the Public Health Ordinance of 1926; (iii) the Public Health Regulations of 1926, both of which provide for public health measures including sanitation, solid waste collection, and drainage; (iv) the Foreshore and Land Reclamation Ordinance of 1969, which regulates extraction of material such as sand, gravel, reef mud, and rock; (v) the Marine Zones (Declaration) Act of 1983, which provides for protection and conservation of the marine environment, where these are not otherwise covered by national or international law; and (vi) the Local Government Act, 1984, which empowers local government bodies to issue by-laws relating to environmental protection. 5. International agreements of relevance to which the Republic of Kiribati is a signatory are (i) the United Nations Convention on Law of the Sea, (ii) the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal, (iii) the London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, (iv) the United Nations Convention on Biodiversity, (v) the United Nations Framework Convention on Climate Change, (vi) the Kyoto Protocol, (vii) the Montreal Protocol on Substances that Deplete the Ozone Layer (and subsequent amendments), and (viii) the Stockholm Convention on Persistent Organic Pollutants.


III. DESCRIPTION OF THE SUBPROJECT

1. Project Type

6. Infrastructure: The subproject will consist of infrastructure improvements and capacity building for improved infrastructure governance. The environmental screening process has followed the appropriate ADB checklists.

2. Project Category

7. The appropriate category for the subproject according to the ADB’s classification is Category B.

3. The Sector Project

8. The subproject will be implemented under the South Tarawa Sanitation Improvement Sector Project, which will have the following outputs: (i) sanitation and hygiene practices among South Tarawa’s population will be improved; (ii) sewerage in South Tarawa will be effectively collected, treated, and disposed of by PUB; (iii) the Ministry of Public Works and Utilities (MPWU) and PUB will have the capacity to effectively and efficiently plan and manage water and sanitation services in South Tarawa; (iv) adequate funds will be available to PUB to finance required sanitation system maintenance activities; and (v) project management services within MPWU will ensure efficient and effective project implementation.

4. Need for the Subproject

9. The sewerage outfalls at the main urban areas on South Tarawa were originally constructed in 1984 and then improved in 2001 under the Sanitation, Public Health and Environment Improvement (SAPHE) Project, but improvements have since failed, and effluent buildup represents a continuing and growing public health hazard. The situation features intense and rapid degradation of the quality of lagoon water and of water in the freshwater lenses beneath the atolls that make up South Tarawa. There are severe occurrences of water-related illnesses, manifested most stridently in the extreme levels of infant mortality, which, at 46 per 1000 live births (almost 5%), is the highest in the Pacific. 10. Outfall pipes were installed by cutting trenches in the flat, intertidal surface above the reef on the ocean side of the island, and then attaching pipes to the outfall pipes, which extended approximately 10 meters (m) beneath the ocean surface. In all cases, the pipes leading from the edge of the reef downward were dislodged. The pipes within the trenches on the flat intertidal areas also suffered ruptures. At Betio,,the effluent is released at the reef edge, just below the ocean surface, but in Bairiki and Bikenibeu, all effluent is released in the intertidal area. Effluent has fecal coliform concentrations of 14,000–100,000 /100 milliliters (mL), compared with acceptable levels for bathing/recreational water use of approximately 200/100 mL, and within the intertidal zone, scope for dilution is limited. 11. The subproject complements further subprojects, which comprise rehabilitation and expansion of sanitation systems and of improved water supplies.


5. Proposed Implementation Schedule

12. Approval for the sector project is expected during 2011, and implementation is due to start in early 2012. Implementation of the subproject will commence with that of the sector project. Construction will commence in Q2 of 2012 and will be completed with the commissioning of the rehabilitated system and equipment in Q4 of 2014.

6. Infrastructure Improvements

13. The scope of the subproject comprises (i) directional drilling through the coral rock to emerge at the sea floor at depths of 25–30m30 m, and (ii) installation of a pipe through the drilled borehole and attachment and anchoring of a suitably designed diffuser at the outlet to ensure rapid dilution at depth. The drilled pipe will, unlike the pipes installed across the reef platform, not be vulnerable to damage by wave surges, currents and boat anchors. Pipe diameters for Betio and Bikenibeu, where the populations of the serviced areas are 15,700 and 7,200, respectively, will be 300mm,300 millimeters (mm), while at Bairiki, where the population in the serviced area is 3,500, 200mm.it will be 200 mm. Rehabilitation of the saltwater intake, the saltwater flushing system, and the sewerage collection system,; and provision of primary treatment through in the form of a milliscreen at the junction between the system outlet and the outfall to collect and package solid items removed by screening are covered under a separate subproject. 14. Drilling techniques have been developed to cope with the challenges posed by coral rock, which feature extremely hard coral heads, interspersed with areas of looser rock. Difficulties arise both from the hardness of the rock and the tendency of rock fragments to fall into the cavity created through looser rock, preventing the insertion of pipes once the drill head is withdrawn. This is overcome by the use of a biodegradable foam that is pumped through the drilling apparatus. Drill rigs will be mounted either on land or on the intertidal flat zone, and the drilling length will be between 315 m for Bikenibeu, 435 m for Bairikiand 995 m for Betio.200 m, depending on the bathymetry at each location. Figure 1, Figure 2, and Figure 3 illustrate the bathymetry at the three sites, while Figure 4 indicates the location of the outfall and of the sewered areas that feed into them. Figure 1: Bathymetry at the Betio Outfall Site


Figure 2: Bathymetry at the Bairiki Outfall Site

Figure 3: Bathymetry at the Bikenebeu Outfall Site


Figure 4: Aerial View of Tarawa Indicating Location of Sewered Areas (in yellow) and Outfalls (red)

IV. DESCRIPTION OF THE ENVIRONMENT

A. Physical Resources

1. Geology, Topography, and Soils

15. South Tarawa comprises a series of atolls, oriented east-west and connected by causeways. It adjoins North Tarawa, which similarly, comprises a series of atolls, orientated approximately north-west south-east. It lies at a latitude of 10o20’ North and 172–173o East, and is approximately 150 kilometers (km) north of the equator. The atolls developed from a volcano that appeared between 55 million and 65 million years ago (during the Paleocene geologic epoch). Over time, the peak of the volcano sunk below sea level as a result of subsidence of the ocean floor. As an atoll, the island surface is formed by successive coral deposits around the old and now submerged volcano. Atolls originate as coral reef formations at the tidal level at the rim of the original volcano, which gradually rise as a rock base forms from the calcium carbonate deposits of dead coral. At various times in the growth of the reef, the sea surface is reached and coral ceases to grow. Growth resumes again when the atoll drops below the surface of the sea. The vertical growth from this process keeps the reefs at or near the surface of the ocean as the volcano subsides. The atoll of North and South Tarawa, and the surrounding reef delineate the edges of the lagoon, which occupies the site of the former volcanic core. South Tarawa has a narrow coral sand beach leading to the lagoon along its north side, and an intertidal platform on its south side, adjoining the ocean.


16. With a high demand for housing and infrastructure and therefore building materials, pressure on beach sand, gravel, and aggregate is intense. This threatens ecosystems and the ability of coastal areas to provide protection from sea surges. However, with carefully planned extraction, adequate supplies of material can be made available at reduced impact. This activity is supported under the Environmentally Safe Aggregates for Tarawa (ESAT) project funded by the European Union (EU). 17. The atolls have soils derived exclusively from coral deposits, predominantly sandy in texture, with a significant silt component formed from abrasion within the sand deposits. Over much of the island, deposition and breakdown of organic matter have led to the formation of a thin layer of topsoil. The soils are free draining when uncompacted, have poor nutrient status, and are generally alkaline. The surface relief is extremely low, with a maximum of 3 m above sea level. Measurements show that gradual uplift is taking place as a result of ocean floor movement on the order of 1 mm per year. However, sea level rise, linked to the phenomenon of climate change, is occurring at a rate of 3-4 mm per year.

2. Climate

18. Tarawa has a maritime tropical climate. Two seasons occur, characterized mainly by the wind patterns but also by rainfall. Between October and March, easterly trade winds predominate and rainfall is generally higher, while between April and September, more variable winds occur including westerlies, which can be strong, and rainfall is lower. Temperatures generally vary between 28°C and 32°C, averaging 31°C, though monthly averages remain very constant between 26°C (February) and 28°C (September). Rainfall averages 2027 mm annually; however, this varies widely between 398 mm and 4333 mm. Rainfall patterns are influenced by the convergence patterns of trade winds. The South Pacific Convergence Zone (SPCZ)), which occurs within the Intertropical Convergence Zone (ITCZ)), has a strong influence on the occurrence of rainfall. The ITCZ is influenced by the El Niño/Southern Oscillation (ENSO): during El Niño events it moves towards the equator, bringing higher rainfall to Tarawa, while during La Niña events the reverse happens. The effects of El Niño/La Niña notwithstanding, climate variability is strongly apparent. The island is subject to intermittent droughts, when the drier season can extend well beyond the months of April to September. Unlike many other Pacific islands, Tarawa rarely experiences cyclones. 19. Ocean currents are influenced by both the westward northern equatorial current and the eastward equatorial counter current, and, particularly at shallower depths, by wind patterns. These influences are complex and have not been investigated over a sustained period in South Tarawa. However, both the ocean currents and the winds act predominantly in east-west directions, parallel to the long axis of the island.

3. Climate Change

20. The incidence and severity of droughts can be expected to worsen with the occurrence of climate change. Climate change is of intense concern, and also carries risks of higher sea surges, hotter or cooler periods, loss of land area, and constriction of freshwater lenses. Predictions from a World Bank study1 suggest that South Tarawa could lose between 25% and

1 World Bank (2000). Cities, Seas and Storms: Managing Change in Pacific Island Economies. Vol IV: Adapting to

Climate Change, World Bank, Washington


54% of its land mass by 2050, and in the recently prepared Tarawa Water Master Plan2, it is predicted that the thickness of the freshwater lenses below South Tarawa may be reduced by 18%-19%.

4. Freshwater Resources

21. Rainwater that is not returned to the atmosphere via evapotranspiration flows into the ground and collects by infiltration through the soil layers, into a lens that forms in the underlying strata of the atoll. The lens is convex in profile, and thickest at the center. The size of the lens is strongly dependent on the width of the island. While this provides a valuable source of freshwater extracted through wells, it is subject to pollution from human and animal waste as well as depletion from overextraction, and to climate variability. Ground water from a designated water reserve at Bonriki in South Tarawa currently feeds a reticulated system, which supplies water disinfected by chlorination to consumers. Neighboring Buota in North Tarawa, which has a significantly lower population density, has addition, although far more limited reserves of groundwater and supplies water to South Tarawa via a pipeline, which is currently being rehabilitated. Desalination of seawater, an energy-intensive and therefore expensive process, is indentified in the Tarawa Water Master Plan as a last resort. B. Ecological Resources

1. Vegetation

22. The present-day vegetation cover on the island is substantially influenced by human habitation and has little biodiversity conservation significance. Conversely, mangroves occur on reef mud flats at the lagoon margins at certain areas, and provide a coastal protection function as well as an important habitat for marine organisms. Mangroves have been subject to depletion, but mangrove forest areas are being rehabilitated by the government under the World Bank-funded Kiribati Adaptation Project, phase II (KAP II). Sea grass beds, which provide an important habitat for shellfish and other organisms, occur extensively within the lagoon, particularly toward the southeast. Recent measurements suggest that the extent of seagrass beds is in fact expanding. 23. Most of the terrestrial vegetation cover features fruit trees and decorative plants. The most common are coconut (Cocos nucifera), casuarinas (Casuarina equisetifolia), breadfruit (Artocarpus sp.), hibiscus (Hibiscus sp.), papaya (Carica papaya), pandanus (Pandanus tectorius), flame tree (Delonix regia), salt bush (Scaevola sericea), and terminalia (Terminalia sp.). These plants are widespread in the Pacific and tropical regions generally, though most are spread primarily by human cultivation. Papaya and flame tree originate from outside the Pacific region.

2. Fauna

24. More important habitats of conservation and biodiversity significance are associated with the marine rather than land environment. Fauna on the island is strongly influenced by human habitation, and there are no significant wildlife habitats. Coral within the lagoon suffers from high turbidity and pollution (mainly in the form of nutrients from human and animal waste), which has an effect on the integrity of the ecosystem. The situation is similar on the intertidal rock platform between the edge of the island and the edge of the reef, which is also subject to release of

2. White, I (2011): Tarawa Water Master Plan Te Ran, Groundwater, Government of Kiribati


human and animal waste. However, at the reef edge, effluent is rapidly diluted by ocean water and coral formations are more intact. These occur most prolifically on a gently sloping terrace that extends out from the reef edge, before the reef slope steepens sharply to a near vertical gradient extending to depths in excess of 1 km. 25. Fish, shellfish and crustaceans are an important source of food to the islanders and are collected extensively in the lagoon or from the ocean. Concern exists over an observed decline of species such as shark, red snapper (Lethrinus gibbus), and crustaceans such as mangrove crabs (Cardissoma sp.). Sea cucumber species are reportedly depleted. Causes are both overexploitation and lagoon water quality.

3. Protected Areas

26. While Kiribati has a number of protected areas, none of these occur on or around South Tarawa. C. Culture

27. The original inhabitants of Kiribati are Gilbertese, a group of Micronesian origin. Culture and traditional practices are strongly upheld by island communities. Having evolved in a high degree of isolation, there are strong indigenous customs. The communities have absorbed the creeds of a number of churches, introduced to the islands by missionaries operating in the Pacific since the late 18th century, and church services and functions are an important part of daily life. 28. Land, land rights, and lagoon rights are subject to traditional ownership. Decisions are made by landowners and village communities. 29. During the Second World War, Tarawa was the scene of significant combat between Japanese and American forces. The large guns installed by the Japanese remain in place and provide a strident reminder of the events in the 1940s. D. Human and Economic Development

1. Population Levels

30. The population density on Tarawa is dense. Even between the main urban areas of Bonriki, Bikenibeu, Bairiki, and Betio, land is almost entirely taken up by residential, commercial, and communal buildings and their surrounding compounds. The population stands at some 50,010 people representing an average population density of around 3,193 people per square kilometer (km2) over the 15 km2 of land area, though in the urban areas such as Betio, it reaches 8,990 people per km2. While measures were taken in the past to encourage migration to outlying atolls, at present extensive in-migration occurs, and the population of South Tarawa is growing by 5.3% per year. In 2010, at the time of the last census, the population of South Tarawa represented some 48% of the total population of Kiribati. The average household size is large, at 7.5 persons, and households with 15 or more inhabitants are not uncommon.

2. Economy

31. The economy of Kiribati features extreme distances between islands (the two gaps between the three island groups are both approximately 1000 km), paucity of natural resources,


and large distances to international markets. Fishing licenses, copra, and seaweed provide some international revenue, and many Kiribati families are reliant on remittances from family members working offshore, often in international shipping. Some tourism takes place. Competition is high among Pacific nations to market traditional attractions such as tranquil secluded beach locations, and Pacific culture, and Kiribati is not well located in terms of proximity to the major markets of the United States, Japan, Australia, and New Zealand and therefore does not compete easily with other tourist destinations in the Pacific. However, war relicts, game fishing, and the millennium islands (whose proximity to the international dateline provides them with the distinction of being the first to celebrate each New Year) encourage some visitors. Visitors number 3,000-4,000 each year and bring some significant revenue. 32. South Tarawa functions both as the nation’s capital and the main seaport and international airport. The service sector accounts for most employment and 80% of jobs are in the public sector.

3. Public Health

33. The incidence of illnesses relating to deficiencies in water supply and sanitation is highly significant. According to the World Health Organization (WHO), infant mortality rate is 46 per 1000 live births, which is the highest in the Pacific and is attributed mainly to diarrhea, to which infants are very vulnerable. Diarrhea is also rife among the adult population, with significant outbreaks occurring as frequently as twice a year, according to local clinics and WHO. While the principal sources of infection are likely to be unsafe practices and poor sanitation infrastructure, infections are also likely to come from immersion in lagoon waters. In addition to the proliferation of diarrheal infection, public health suffers from unsafe nitrate levels in well water and worm infestations.

V. ANTICIPATED ENVIRONMENTAL IMPACTS AND MITIGATION MEASURES

A. Method of Assessment

34. Potential impacts were assessed by means of a site visit, discussions with local authorities and members of the public, and subsequent discussion with the project preparation team during concept development for sanitation improvements. The assessment involved consideration of each phase of design, construction (including techniques and materials to be used), and operation (including the main tasks involved in operation and maintenance). 35. Direct impacts from physical works are mainly localized, occurring in and around the target areas. Benefits will be essentially sectorwide, as the three urban areas of Betio, Bairiki, and Bikenibeu cover the majority of densely populated urban areas in the Republic of Kiribati. B. Impacts Related to Location

36. The outfalls will conduct effluent from the densely populated builtup areas of Betio, Bairiki, and Bikenibeu to the ocean, discharging effluent below the belt at which coral occurs via a pipe placed by directionally drilling through the coral rock. There will therefore be little or no effect on areas of biodiversity conservation significance on land or on the intertidal platform between the edge of the island and the edge of the reef. Effects on the coral colonies will be substantially avoided during construction by the use of directional drilling, obviating any need to place structures or dig trenches through the live coral belt and avoiding disturbance to the marine habitat of the reef flat and reef edge. Effects on coral during drilling will be mitigated by


discharging effluent near or below the lower limit of live coral, and placement of a multi-orifice diffuser fitting to ensure rapid mixing and discourage the deposition of nutrients on the coral. C. Impacts related to Construction

37. Temporary impacts will result from subproject works such as noise and dust nuisance, generation of construction and other waste, and risks of damage to property and utilities and of spillage of fuels or chemicals used in construction. These impacts, as well as being confined to the construction period, can be substantially mitigated by placing obligations on contractors to adopt high standards of supervision, site management, and public information. Because of the use of drilling, no damage to live coral will take place. The drilling rig will be located either on the island or on the intertidal platform, and directional drilling will pass underneath the live coral layer. 38. Potentially, the most significant impact from construction is the release of particles into streams and then to coastal and lagoon waters, contributing to existing problems with the lagoon water quality, and the quality of water on the intertidal platform. This impact relates to excavation operations and to temporary storage and final disposal of spoil. However, there is significant demand for sand and aggregate for building purposes, and any excavate that is surplus to requirements for backfill can be provided for this purpose. Risks of release of spoil can therefore be mitigated by identifying buyers (or nonpaying recipients if appropriate) of sand and aggregate, minimizing the period for which spoil is piled on-site after excavation and, where warranted, by the use of sediment traps around worksites to substantially reduce the release of fine particles into streams. D. Impacts Related to the Operation Phase

1. Public Health and Marine Ecosystems

39. The integrity of the ecosystem in the lagoon, the quality of lagoon water and of groundwater, and the effects of human health are to be specifically addressed by the subproject. Collection and discharge of human waste to the ocean outfall will enable rapid dilution of effluent, place pathogens in an environment where they will be rendered harmless by salt concentrations and sunlight, and lower nutrient concentrations at the ocean surface, while ultimately the nutrients will be widely dispersed within the ocean and taken up by living organisms to reenter the food chain. This will significantly alleviate the current situation, where nutrients and pathogens enter the freshwater lenses or lagoon and accumulate. 40. The extent to which nutrients and pathogens are diluted by seawater before reaching the surface, where some fishing and bathing take place, is governed by the level of dilution achieved on release at the outfall opening, salinity, temperature, water currents at and above the point of release, the rate of further dilution as the plume rises to the surface, and the direction of travel of the plume. The dilution of effluent will be maximized by ensuring that release occurs at a depth of 20–35 m beneath the water surface (compared with the current situation, where release occurs near the surface or within the intertidal zone); the fitting of a multiport diffuser at the outfall opening, which will cause effluent to be released in a series of small jets, facilitating near field dilution; and physical separation between the outfall and the intertidal area, where bathing and fishing take place. Some data are available on the existence of currents that would disperse the plume, based on observations of drogues released at the intended outfall sites, carried out for the design of outfall improvements in 1999. These data show that currents of up to 1 m/second occur and that the direction of travel is generally parallel


to the coastline. Prevailing winds that drive the currents come predominantly from the east during the trade wind season, though they are more variable for the rest of the year. Most winds blow parallel to the coastline and therefore, in most cases, it is unlikely that the plume will move directly onshore. Concentrations of fecal coliform at each site were determined during the preparation of the SAPHE project and found to range from 14,000 /100 mL to 100,000 /100 mL. Calculations undertaken by the project preparatory technical assistance engineering team predict an approximate effluent flow through each system of 0.01 cubic meters/ second. 41. The key variables of discharge depth, outlet port design, port diameter, effluent flow rate, and concentration of fecal coliform in the effluent, along with assumed values for temperature and salinity, were input to the effluent plume prediction model VPLUME produced by the United States Environmental Protection Agency3 to determine levels of dilution, an indication of plume movement, and predictions of the concentration of fecal coliform at the surface. 42. Applying predicted values (Table 1), a dilution factor of 3,438 and fecal coliform, concentrations at the surface of 28/100 mL are expected for normal conditions. This constitutes normal outflow at an assumed current of 0.1 m/second. This compares favorably with an acceptable water quality standard for recreational use of 250 fecal coliform/100 mL.4 The plume begins to rise to the surface just around 45 m from the point of release. Applying a “worst-case” scenario, where a peak flow of six times the normal flow is predicted and there is no current, a considerably lower dilution factor of 196 is achieved and the concentration of fecal coliform at the surface is 502/100 mL. The center of the plume rises to the surface some 21 m from the point of release. The plume elevation profiles for the two situations are shown in Figure 5. Figure 5: Plume Elevation Profiles for Predicted Situation (left) and Worst-Case Situation (right)

3 http://www.epa.gov/ceampubl/swater/vplume 4 The preferred water quality indicator adopted by WHO is number of enterocci/100 mL. However, data on

enterococci concentration are not currently available, and the WHO standard of 140 enterococci/100 mL for water for recreational use has been found to equate to approximately 250 fecal coliform/100 mL.


43. To quantify the effects of the variables on the level of dilution achieved and predicted surface concentration of fecal coliform, the model was run for a predicted, maximum, and minimum value for each variable. The results are presented in Table 1 below. Table 1. Predicted Surface Concentrations of Fecal Coliform

Variable Predicted Value

Minimum/Maximum Dilution Factor

Fecal Coliform Surface

Concentration (MPN/ 100 mL)

Port diameter 10 mm Min 5 cm 2974 33Max 20 cm 4292 23

Number of ports (assuming 5-cm ports)

50 Min 20 129 761

Max 150 170 580Depth of outfall opening

25 m Min 20 m 2268 43Max 30 m 4814 20

Current speed 0.1 m/s Min 0 m/s 342 287Max 2 m/s 10159 10

Effluent discharge rate

0.01 m/s Min 0.005 m/s 6439 15Max 0.02 m/s 728 135

Concentration of fecal coliform

100,000/ 100 mL

Min 14,000 3438 4

Max 150,000 3438 43Effluent salinity 16 psu Min 12 psu 3322 30 Max 20 psu 3483 28Effluent temperature

23oC Min 20oC 3445 29Max 26oC 3359 29

44. The VPLUME model demonstrates that the level of dilution achieved varies markedly with current flow, and that variables that can be manipulated (number and diameter of ports) have a strong effect. The system is sensitive to any substantial increase in the concentration of fecal coliform in the effluent, and to an increase in discharge rate. The comparison presented in Table 1 demonstrates that it is likely that concentrations of fecal coliform as high as 250/100 mL will occur on occasion, though usually only under very still conditions. 45. Coral growing above the outfall openings may be affected by the effluent discharge. A survey of the effects of the outfalls was commissioned by the steering committee and project management office of the SAPHE project in 2005. The survey found some accumulation of algae and increased occurrence of dead coral as well as lower species diversity near the outfall openings. These are attributed to changes in nutrient load in the water near the outfalls. While these will occur near the improved outfalls, rapid mixing is likely to render concentrations of nutrients and nonsaline water too low to affect corals, and a greater portion of effluent will drift out to sea. While some localized effects may occur, it is likely that much of the existing coral colonies will benefit in the long term from effective dispersal of the effluent plume. 46. The analysis of alternatives in section VI demonstrates that greater levels of pretreatment or more distant point of release are infeasible.


E. Treatment of Risks associated with Climate Change and Variability

47. The current climate change assessment report of the Inter Governmental Panel on Climate Change5 emphases risks related to sea level rise, sea surge risks, temperature rise, decreases in rainfall (whether long term or in terms of extreme dry years or season) and storm severity. The main vulnerabilities faced by the people of Tarawa can be summarized as (i) sea-level rise which exacerbates the severity of sea surges, increases rates of coastal erosion and heightens risks to public and private infrastructure (ii) more intense and more frequent storms which increase risks of damage from sea surges, high winds and strong inundation on public and private infrastructure and (iii) more frequent and longer periods of drought: which cause both intense short term difficulty and, of greater concern, long term damage to the freshwater lenses that exist beneath the islets. 48. The use of an ocean outfall for the treatment of sewage by dilution and rapid dispersal is the preferred response to the risks of sea surges and inundation as well as shrinkage of land area, that are anticipated from climate change. Any land based system would involve the use of ponds or tanks that contain partially treated sewerage, which would be released and spread in the event of inundation, greatly increasing the spread of waterborne disease. 49. In response to the urgency of conservation of freshwater lenses, saltwater is chosen as the flushing medium for the systems, reducing reliance on well water for this purpose. 50. Risks of inundation, and strong currents associated with more frequent and severe storm events as well as increasing coastal erosion are addressed by the chosen option of drilling through coral rock to provide a very strong pipe conduit to the ocean outfall. F. Summary of Subproject Impacts and Mitigation

51. Table presents the expected impacts related to location, the construction phase, and the operation phase. It shows the assessment of impacts as minor, moderate, or major in consideration of the scale of the change to be brought about by the project and the significance of the change to human populations. In each case, changes may be positive or negative. “No impact” refers to cases where no change is expected to occur as a result of the project, or changes are expected to be negligible. Mitigation measures have been identified to avoid or ameliorate potential negative impacts.

5 The Intergovernmental Panel on Climate Change is a scientific body established by the United Nations Environment

Programme and the World Meteorological Organization in 1988 as the leading international body on the assessment of climate change, and is based in Geneva.


Table 2: Screening of Environmental Impacts and Mitigation Potential Environmental Impact

Nature and Duration Location Mitigation Measure(s) Assessment of Impact With/Without Recommended Mitigation

Temporary or Permanent

Impacts due to Location

Encroachment of precious ecological areas.

The improved outfalls will reduce the amounts of nutrients and nonsaline water that currently damage corals growing along the coastline. Effects are discussed further under impacts due to operation.

On the sea bed, near the outfall openings

Increased depth of outfall openings and use of diffuser fittings to enhance initial mixing and facilitate plume dispersal

Positive impact Permanent

Historical/cultural monuments and values

No monuments or relics of cultural value exist in the project area.

n/a n/a n/a n/a

Resettlement / loss or damage to property

Any temporary occupation of land or property for the placement of the drilling rig will be addressed under the land acquisition and resettlement plan.

Work sites near each outfall location

Compensation as provided for in the Resettlement Plan for the project

Moderate / minor Temporary

Impacts related to Construction

Accidental damage to utilities

Not significant, as work sites occur at the edge of the island or in the intertidal zone, not close to any property or utilities

n/a n/a n/a n/a

Generation of construction waste

Material produced by excavations will be sold or distributed for reuse. Waste products from construction works will include empty fuel drums and other packaging materials.


Arrangement for sale or distribution of excavated materials; use of bins and skips at construction site for the collection of waste; removal to landfill; separate collection of fuel drums and any other containers that have held hazardous chemicals

Minor / eliminated Temporary


Potential Environmental Impact



Noise and dust nuisance from construction activities.

Noise and dust is likely to be caused by drilling operation and movements of vehicles and will cause some nuisance .


Providing information to nearby residents about the duration of noise and dust-generating operations; planning of construction operations to minimize public nuisance; limit construction operations to take place during daytime hours (7am to 6pm) only.

Minor / minor Temporary

Pollution from chemicals and fuels

Improper storage and handling of chemicals and fuels used in the drilling operations pose a risk at construction sites. The impact will be temporary, as the risk will be confined to the construction period.


Secure and controlled storage of all toxic and hazardous materials including fuels; requirement to ensure that the drilling rig and any vehicles are in sound operable condition, preventing oil leakages and excessive exhaust emissions.

Moderate / eliminated

Temporary

Safety hazards to workers and the public

Workers or members of the public may be exposed to the risk of accidents during construction. The risk will be temporary and confined to built-up areas during the construction period.


Requirement for the contractor to submit a safety plan that covers, at a minimum (i) allocation of responsibility and training of workers on safety precautions, for themselves and others and for implementing emergency procedures; (ii), provision of protective clothing and equipment to workers as appropriate; (iii), ensuring that vehicle and equipment operators are properly licensed and trained; (iv) arranging for provision of first aid facilities; (v) emergency evacuation procedures; and (vi) provision of hazard warning signs at the construction sites

Moderate / minor Temporary





Impacts during Operation

Public health Substantial improvement, through diversion of nutrients and pathogens from the freshwater lenses or lagoon to the ocean. However, any onshore movement of the effluent plume may result in unacceptable water quality for bathing and fishing

The intertidal zone near each outfall, where fishing and bathing take place

Construction of robust outfalls opening at depths of 35–40 m below sea level; fitting of diffuser device to ensure high level of near field mixing.

Significant / minor or insignificant

Permanent

Effects on marine ecosystems

Significant improvement over existing situation, where effluent is released in the intertidal zone or close to the surface of the water, in high concentrations

The sea floor, beyond the reef edge, where living coral colonies occur

Construction of robust outfalls opening at depths of 35–40 m below sea level; fitting of diffuser device to ensure high level of near field mixing

Significant / minor or insignificant

Permanent

Effects of breaches of the outfall pipeline

Any breaches of the outfall pipelines will result in the release of concentrated effluent in the intertidal zone, possibly causing eutrophication and reducing water quality to unacceptable levels both for recreational water use and for the integrity of coral colonies.

Intertidal zone and sea floor beyond the reef occupied by live coral colonies

Use of directional drilling through the coral rock, eliminating the vulnerability of the pipeline to damage from currents or boat anchors, avoiding the potential destruction of the marine habitat

Significant / eliminated

Permanent

Effect of damage to diffuser fittings

Any damage to diffuser fittings at the outfall openings will result in greatly reduced nearfield dilution of effluent, causing limited dispersal of the plume, and greater concentrations of nutrients, pathogens, and nonsaline water released near coral colonies.


Appropriate design and construction of the diffuser fittings to ensure they are adequately robust to last the design life of the system

Significant/ minor Permanent


VI. ANALYSIS OF ALTERNATIVES

52. To achieve sanitary living conditions in the serviced areas by effective removal of pathogens contained in the effluent and to prevent pollution of groundwater and lagoon water from effluent, one or a combination of three measures can be taken: (i) treatment of the effluent, (ii) increased separation of the point of discharge from the receptor population, and (iii) dilution of the effluent to bring the concentration of pathogens to acceptable levels. The proposed subproject utilizes the second two measures, namely separation of the point of discharge from the receptor population by a horizontal distance of approximately 150–200 m and a vertical distance of 25–30 m beneath the ocean surface and rapid dilution both nearfield (at the point of discharge) and as the effluent plume rises within the ocean water and is dispersed by currents. Greater separation would involve drilling to a greater depth, which is considered infeasible because of the difficulties and costs of undertaking construction work at depths in excess of 30 m, and dilution is to be optimized by the design of the diffuser fitting at the outlet of the outfall. Alternatives are limited to (i) a greater level of treatment (prior to discharge into the outfall or instead of an outfall), and (ii) the “do-nothing” option. 53. Scope for the alternative of a greater level of effluent treatment is limited by space availability. The treatment of effluent involves settlement to collect solids and biological treatment, wherein harmful components of the effluent are broken down by aerobic processes. Both of these processes require the effluent to remain in ponds for a period. Ponds would have to be sited well away from the coast, and would require in excess of 1,600 m2 in each location. In each case, homes are situated around the serviced areas, and the provision of such a facility would require significant involuntary resettlement and land acquisition at considerable cost. The option is considered infeasible on the grounds of (i) cost, and (ii) the spread of contamination in the event of a major sea surge. 54. Under the “do-nothing” option, existing unsanitary living conditions in and around the three urban areas and the buildup of pathogens in the intertidal platform area would continue at an accelerated rate as the population grows, creating more extensive and severe unsanitary living conditions. This would significantly exacerbate the existing levels of child mortality and morbidity, which are already high by Pacific standards and considered unacceptable.

VII. INFORMATION DISCLOSURE, CONSULTATION, AND PARTICIPATION

55. During project preparation, both formal and informal consultations took place with participants from the three urban areas and the wider public. These included informal discussions with residents within and outside the sewered area during site visits; formal meetings at community halls (maneabas); focus group discussions with women, men, youth, and children; and a questionnaire survey. The consultations covered disclosure of information to the public on the project and its proposed scope, information and views on the existing sanitary situation, information on the state of sanitation infrastructure, sanitation arrangements in individual homes, attitudes to defecation, understanding of links between poor sanitation and disease, information about the environment, and concerns and views relating to construction. 56. The principal findings from the consultations were as follows: (i) the outfall at Bikenibeu and at Bairiki had ceased to function around 2 years ago, and there are some leaks in the outfall pipe at Betio; (ii) where the outfall has failed, a buildup of sludge develops at the shoreline and bad odors persist; (iii) the sewerage system in each town does not operate well, and large quantities of well water are required to flush toilets; (iv) many homes within the sewered area are not connected to the system; however, householders continue to arrange connections, often


undertaking the work themselves, while others construct septic tanks; (v) defecation at the beach remains widespread, is often preferred over using a toilet, and is even considered to be a social activity; (vi) householders with functional toilets often allow neighbors and their visitors to use their toilets; however, some people are often embarrassed to ask for the use of a neighbor’s toilet; (vii) few people have an understanding of how disease is transmitted, and few wash their hands after defecation; and (viii) residents near the outfalls are aware that drilling operations will be noisy and dusty, but they know that these effects will be temporary, and that the outfalls will reduce the problem of bad odor. 57. During construction, the contractor will disclose information on the location and duration of construction operations.

VIII. GRIEVANCE REDRESS MECHANISM

58. Members of the public will have the right to make grievances known to MPWU and the right for them to be addressed, to the extent practicable and reasonable. 59. During construction, a member of the supervising consultant’s team will be assigned the role of community liaison for each of the three urban areas. The name and contact details of these individuals will be presented on a notice board at work sites and at MPWU, with instructions on how to make a complaint. For minor complaints, such as noise or dust nuisance, or disregard of safety procedures, corrective action will be instructed by the supervising consultant, and a response provided to the complainant within 48 hours. If no action is deemed appropriate, the complainant will be apprised of his/her rights to take the complaint to the Magistrate’s Court. 60. For complaints about major issues such as injury, damage to property, or occupation of land without due agreement, the supervision consultant will respond within 24 hours and arrange a meeting with appropriate personnel including a representative of MPWU to agree on resolution. If a solution, agreeable to all parties, is not reached within a period of 7 days, the complainant may file the grievance with the Magistrate’s Court, which involves a registration fee of $3.00. The Magistrate’s ruling will be binding on all parties. 61. A register of complaints will be maintained at the MPWU recording dates, names of complainants, action taken and personnel involved.

IX. INSTITUTIONAL REQUIREMENTS FOR ENVIRONMENTAL MANAGEMENT AND MONITORING

A. Implementation Arrangements and Institutional Responsibilities

62. The executing agency for the sector project is the Ministry of Finance and Economic Development (MFED), and the implementing agency is MPWU. The implementing agency will have primary responsibility for monitoring, the review of monitoring reports, and response to issues presented in them. These functions will be carried out by a Project Implementation Unit (PIU) established within MPWU, which will act under the direction of a Project Steering Committee (PSC), with representation from the key stakeholder ministries and local government bodies6 and chaired by the Secretary to the Cabinet. The Ministry of Health and Medical

6 Members of the PSC are the Secretary to the Cabinet (chairperson),); Secretary for Finance,; Secretary for Public

Works and Utilities,; Secretary for Internal and Social Affairs,; Secretary for Health and Medical Services,;


Services (MHMS) will provide laboratory services for water quality tests. The Ministry of Environment, Land and Agricultural Development (MELAD) will review monitoring reports for compliance with the Environment (Amendment) Act 2007 and the conditions of environmental license. 63. During construction, a construction supervision consultant will have responsibility for monitoring compliance with the Environmental Management Plan (EMP). B. Environmental Monitoring

64. The key indication of the effectiveness of the outfalls in achieving adequate dispersal of pathogens and nutrients is the quality of water at the ocean surface and the intertidal zone. The principal monitoring need is to determine the extent to which water quality at the coastline is kept to acceptable levels. An appropriate indicator of acceptable water quality can be taken as 200 enterococci/100 mL of water. This is the guideline for bathing water quality recommended by WHO7 based on the correlation of the occurrence of enterococci as fecal indicator bacteria with the incidence of waterborne disease. MHMS has confirmed that it can test water for enterococci levels, provided a budget is available for reagents. Further parameters are total phosphorus, total nitrogen, and total Kjeldahl nitrogen (TKN). 65. Measurements will be taken in the intertidal zone and immediately beyond the reef edge. Ten samples should be taken, approximately 30 cm below the surface, and at the same tidal phase (for convenience, this may be peak high tide). The measurements should take place prior to construction to establish baseline levels, and then during construction and operation at quarterly intervals. 66. Information on observable changes resulting from the works, as reported by local communities, is also of value. For the construction phase, monitoring of compliance with the mitigations specified in the Environmental Management Plan (EMP), both during detailed design and construction, is necessary. 67. The monitoring plan (Table ) summarizes the required monitoring activities, parameters to monitor, responsibilities, and costs.

X. ENVIRONMENTAL MANAGEMENT PLAN

68. Table describes the mitigation measures required for design, construction and operation of the improved outfalls, as well as the cost and responsibility allocation arrangements. Overall responsibility for implementing the Environmental Management Plan rests with MPWU, which, during design and construction, will be supported by the PIU. Responsibility for incorporating mitigation into design rests with MPWU, supported by the project implementation consultants. 69. Responsibility for carrying out environmental mitigation of construction impacts rests with the contractor, while MPWU, with the assistance of the supervision consultant, is responsible for ensuring compliance. The EMP should form part of the works contract documentation so that the contractor incorporates the cost of mitigation into the bid price, including provision of staff and equipment necessary to carry out all mitigation tasks in full.

Secretary for Environment, Lands and Agriculture Development,; the Mayor of the Teinainano Urban Council; and the Mayor of the Betio Town Council.

7 WHO (2003) Guidelines for Safe Recreational Water Environments: Volume 1 Coastal and Freshwaters. World Health Organization, Geneva.


70. During scheme operation, responsibility for mitigation rests with MPWU.

XI. FINDINGS AND RECOMMENDATIONS

71. Environmental screening has included site visits, consultations with a range of project stakeholders, and a review of documentation. No significant negative environmental impacts are envisaged, although the extent of impacts from effluent release cannot be determined with a high level of accuracy. The construction of outfall pipes through coral rock, achieving a robust construction and significant depth below the surface, will increase physical separation and the efficiency of dilution of the effluent plume. There is no practicable alternative to achieving safe sanitation while protecting the lagoon and freshwater lenses from pollution. The EMP covers key design considerations related to sound construction and long-term serviceability of infrastructure including requirements for high standards of construction supervision and provisions to mitigate environmental effects during construction such as noise and dust nuisance, safety, and impedance of traffic. The EMP plan provides for community feedback, linkage with ongoing water quality monitoring programs, and monitoring for compliance with the EMP.

XII. CONCLUSION

72. The overall finding of the IEE is that the subproject will not cause significant environmental problems and that potential adverse impacts are manageable through the implementation of the EMP. No further environmental assessment is therefore required, beyond the issues to be reviewed during detailed design. 73. The subproject can therefore be classified under Category B: Projects judged to have some adverse environmental impacts, but of lesser degree or significance than those for Category A projects.


Table 3: Environmental Management Plan


Location Mitigation Measure(s) Cost Allocation

Responsibility for Implementation

Preconstruction Stage

Encroachment of precious ecological areas.

Impaired public health from poor water quality

On the sea bed, near the outfall openings

Ensure design depth of 25 m or greater

Design of diffuser fitting to optimize dilution

Design cost Design consultants

Resettlement / loss or damage to property


Compensation as provided for in the Resettlement Plan for the project. RF budget MPWU

Safety hazards to workers and local people, and effects of temporary worker populations in the area


Preparation by the contractor of a safety plan that covers, at a minimum (i) allocation of responsibility and training of workers on safety precautions, for themselves and others and for implementing emergency procedures; (ii), provision of protective clothing and equipment to workers as appropriate; (iii), ensuring that vehicle and equipment operators are properly licensed and trained; (iv) arranging for provision of first aid facilities; (v) emergency evacuation procedures; and (vi) provision of hazard warning signs at the construction sites

Construction cost

Contractor

Construction Stage

Generation of construction waste


Arrangement for sale or distribution of excavated materials. Use of bins and skips at construction site for the collection of waste. Removal to landfill. Separate collection of fuel drums and any other containers that have held hazardous chemicals.

Sea dumping not allowed

Construction cost

Contractor



Location Mitigation Measure(s) Cost Allocation

Responsibility for Implementation

Accidental damage to property


Careful site supervision by the contractor’s staff, operation of the grievance redress mechanism

Construction cost

Contractor

Noise and dust nuisance from construction activities.


Providing information to nearby residents about the duration of noise and dust generating operations.

Planning of construction operations to minimize public nuisance. Limit construction operations to take place during daytime hours (7am to 6pm) only.

Construction cost

Contractor

Pollution from chemicals and fuels


Secure and controlled storage of all toxic and hazardous materials including fuels.

Requirement to ensure that the drilling rig and any vehicles are in sound operable condition, preventing oil leakages and excessive exhaust emissions.

Construction cost

Contractor

Safety hazards to workers and the public


Implementation of contractor’s site safety plan Construction cost

Contractor

Operation

Continued integrity of the outfall pipes and operation of the diffuser fitting


Water quality monitoring to detect possible loss of performance of the diffuser fitting and leakage

Maintenance cost

MPWU


Table 4: Monitoring Plan

Impact to be Monitored Parameters Location Measurements Frequency Cost Responsibilities

Design and Preconstruction Phase

Health and safety and welfare of workers and the public

Compliance with EMP requirement for the contractor to prepare and submit a safety plan

All work sites / worker accommodation

Compliance Once Negligible MPWT / consultant

Baseline testing of marine water quality in the intertidal zone and in the ocean, 10 m beyond the reef edge

Laboratory testing for enterococci, total phosphorus, total nitrogen and total Kjeldahl nitrogen (TKN).

(i) in the intertidal zone, and (ii) in the ocean, 10 m beyond the reef edge

Concentrations of each pollutant

Once $56a Arranging for testing: MPWT/consultant

Carrying out the testing: MHMS

Construction Phase

Testing of marine water quality in the intertidal zone and in the ocean, 10 m beyond the reef edge

Laboratory testing for enterococci, total phosphorus, total nitrogen and TKN.



Once before, and once after construction

$1,130 Arranging for testing: MPWT/supervision consultant


Distribution or sale of excavated materials; no dumping into the sea

Compliance Drilling sites Observations Continuous during construction

Negligible MPWT / supervision consultant



Information to villagers, and adequate site supervision to take all reasonable steps to limit nuisance. Limiting drilling and other noise and dust generating operations to daytime hours (7am to 6pm) only.

Compliance Homes near drilling sites

Observations and consultations

Observations continuous during construction; consultations weekly

Negligible PPWT / PPO

Storage of all toxic materials including fuels in a secure location, with adequate provision to prevent spillage and seepage into the ground.

Maintenance of the drilling rig and any vehicles in sound operable condition, preventing oil leakages and excessive exhaust emissions.

Compliance All work sites Observations Continuous during construction


Adherence by all contractor’s staff to the contractor’s safety plan

Compliance All work sites Observations Continuous during construction


Operation Phase

Incidence of water-related diseases

Changes in frequency of occurrence of waterborne diseases

Residents of Betio, Bairiki, and Bikenibeu

Collection of data from hospital / health authorities

Annually Negligible Providing information: MHMS

Reporting: MPWU

Perceptions of water quality Opinions of community members

Residents of Betio, Bairiki ,and Bikenibeu

Consultations Twice each year Negligible MPWU



Testing of marine water quality in the intertidal zone and in the ocean, 10 m beyond the reef edge

Laboratory testing for enterococci, total phosphorus, total nitrogen and TKN.



Twice each year $1,130 per year

Arranging for testing: MPWU


a Based on an estimated costs of $95 per set of tests, freight of reagents and test vessels only. The assumed period of drilling is 8 months.

Documents

Initial Environmental ExaminationLinked Document 13 South Tarawa Sanitation Improvement Sector Project (RRP KIR 43072) INITIAL ENVIRONMENTAL EXAMINATION OF OCEAN OUTFALLS SUBPROJECT