Environmental Assessment (EA)

Environmental Assessment (EA)

Saint Lucia Water Supply Infrastructure Improvement Project

]March 25, 2005

Prepared for the World Bank

1.EXECUTIVE SUMMARY1

2.INTRODUCTION3

3.DESCRIPTION OF ALTERNATIVES3

3.1. Alternative 1 – Improve Capacity of Existing System (Capacity Improvement) 4

3.2.Alternative 2 – Installation of a Mobile Desalination

Plant at Pigeon Point (Desal- Plant) 11

4.REGULATORY AND LEGAL FRAMEWORK12

4.1. General Legislative Authorities12

4.2. WASCO legislation13

4.3. Public Health Legislation and Regulations17

4.4. Employees (Occupational Health and Safety)

Act No 10 of 198518

4.5. International Treaties18

5.DESCRIPTION OF ENVIRONMENT21

5.1.Physical21

5.2. BIOLOGICAL23

5.3. Socioeconomic27

6.ANALYSIS OF IMPACTS AND MITIGATION36

6.1.Summary Overview36

6.2. Alternative 1 – Improve Capacity of Existing System (Capacity Improvement) 37

6.3.Alternative 2 – Installation of a Mobile Desalination

Plant at Pigeon Point (Desal- Plant) 44

7.ENVIRONMENTAL MANAGEMENT PLAN52

7.1.Contract development52

7.2. Vigilance53

7.3. Close out53

7.4. WASCO Responsibilities53

8.MANAGEMENT RECOMMENDATIONS54

9.INSTITUTIONAL IMPLEMENTATION54

10.CAPACITYBUILDING54

APPENDICES -

APPENDIX I, IUCN Criteria for Critically Endangered, Endangered and Vulnerable

APPENDIX II, DRAFT ENVIRONMENTAL MANAGEMENT CONTRACT CLAUSES

Page 1

EXECUTIVE SUMMARY

The urgent need to improve the availability of good quality drinking water in the northern section of St. Lucia is obvious. Current inadequacies of the distribution system coupled with the demands for growth in the region are placing increasing pressure on the distribution system. The ability to service all population segments is a priority with the greatest benefit going to low income families. At risk groups include children under 5 and the elderly. These groups will realize a greater proportional benefit from improved access to public water supplies. The impacts associated with both alternatives differ widely given the technologies involved and the users served by the two options. Both options will result in induced development in the extreme northern service area (RodneyBay, Grose Islet) as pent-up development demand is currently frustrated due to lack of water. Numerous communities have been designed and laid-out with supporting infrastructure but are not developing due to poor land sales. There are also plans for the construction of no less than 4 new hotel complexes in the region.

Environmental Impacts

Generally, impacts associated with the first alternative – Capacity improvement, are related to construction activities at the work site. Only those portions of the project involving the construction of new pipelines will affect the community at large as these works will require access to private lands. Those works to occur in public roadways present additional but manageable impacts. The greatest positive impact associated with this option is that it improves the ability to provide a reliable supply of potable water throughout the Theobolds WTP service area and reaches into low income communities where service is poor or non-existent. These are the groups least able to afford developing alternative sources to public water supply.

While this option will result in the continued development of the extreme northern service area, the infrastructure and current supply are adequate to meet the current and anticipated future demand.

The second option, the Desal-plant, provides water only to a specific section of the Theobolds WTP area. While it would relieve the system of short term demands emanating from that area, it would not permit the other improvements necessary to reliably supply water throughout the Theobolds WTP service area.

Aside from the greatly increased costs of water production, the desal option contains a variety of other environmental consequences. These include for example, aesthetic issues, management of seawater intake and brine discharge, chemical pollutants, ecological and marine habitat concerns, issues associated with endangered species and increased energy demands. Furthermore, it is clear, given the pressure for growth in the plants service region, that the demand on the system will quickly increase as new construction begins again in the belief that water is readily available. Finally, the service area for the desal plant represents one of the highest income areas of the island where the average household income is nearly double the national average. This indicates that the direct benefits of this option will not be distributed among the middle to lower income brackets more prevalent in the greater northern service area. The additional cost associated with the production of desalinated water would not be borne by the local service area but would necessarily be folded into the general cost of WASCO water production. Paying for this additional cost would have to be distributed across the entire population through the entire system. Absent a special use fee for the service area, the result is a form of water subsidy for the most affluent portion of the country.

Comparison of Alternatives

Of the two options, option 1, Capacity upgrade, produces the greatest long-term benefit for the entire service area and addresses the total water demand over the next 10 – 15 years. The capacity upgrades clearly meet the long term growth requirements of the northern section with greater reliability, lower cost, and fewer significant direct environmental impacts than the desal option.

Neither alternative has constructions planned in an area suspected of containing undiscovered artifacts or areas of cultural-historical significance.

Page 1

INTRODUCTION

A program of improvements to the St. Lucian public water system is contemplated to alleviate the shortages currently experienced in the northern portion of the distribution system. The two scenarios examined include:

Improvements to increase the capacity of the current system

Installation of a 20,000m3/day desalination plant

Of the two options, the improvements to existing capacity has the greatest impact on the service region by making water available to a wider segment of the population. The Desalination plant is planned in a sub-region of the northern part of the island and while alleviating the short-term demand for water, services a limited population in an explosive growth area. In either case, development in the north is hampered by the lack of water. This report explores the environmental impacts associated with the two alternative projects.

DESCRIPTION OF ALTERNATIVES

Two alternatives are under consideration for the improvement of potable water services under this project. The first involves the improvements to existing infrastructure and the amplification of the existing water treatment facility at Cicero. As the map indicates, figure 3.1, this system is connected to the John Compton reservoir the principal source of water to the north end of the island.

The second alternative is the installation of a containerized desalination plant at the north end of the island. This plant would be built with a 20,000 m3/day production capacity. The objective of both alternatives is to improve water availability to the northern end of St. Lucia and areas in the vicinity of Castries which currently receives limited or intermittent service.

This program is part of a comprehensive strategy to strengthen the water sector, which is essential to the economic development and growth of Saint Lucia. The sector has tremendous impacts on health, agriculture, tourism, industry and the quality of life.

It is important to note that the benefits of the recommendations outlined can only be realized with the implementation of the capacity upgrades recommended for the entire Roseau System. Calculations illustrate that the 2003 demand exceeds the capacity of many of existing components in the Roseau System. As indicated

Table 3.0 below summarizes the current and projected demands as well as the existing capacities of the infrastructural components required for production.

Table 3.0

Current & Projected Demands (Roseau System)

SYSTEM / Existing Capacity (MGD) / Demand 2003*
(MGD) / Demand 2010*
(MGD) / Demand 2015*
(MGD) /

Demand

2020*
(MGD) / Demand
2025*
(MGD)
ROSEAU SYSTEM
a) Pumps
b) Pipeline
c) Treatment Plant / 6.20 (max)
6.00 (max)
6.20 (max)
6.20 (max) / 7.19 / 8.66 / 9.92 / 11.41 / 13.16

Improvement to existing infrastructure comprises a 4 part program designed to improve treatment and distribution for the northern end of the Island. Project elements include:

John Compton Dam Pumping Upgrade

Removal of Vanard-Sarot Bottleneck

Expansion of the Theobalds Water Treatment Plant (WTP)

Upgrade of Morne-Bocage Distribution Line

3.1. Alternative 1 – Improve Capacity of Existing System (Capacity Improvement)

3.1.1. John Compton Dam Pumping Upgrade

The John Compton Dam pumping facility is the primary intake, transmission and distribution of raw water in St Lucia. The sequence of operations that form part of this facilty require extraction of water from a built-up dam using a parallel-pump configuration consisting of five (5) pumps, pumping in sequence to a collecting tank located at the Millet Ridge which flows by gravity to the Theobalds Water Treatment Plant at Ciceron in Castries. See Figure 3.1.

Currently, the existing configuration cannot meet the forecasted demand for the year 2000 and beyond, to the year 2025. recommendations for an upgrade to the facility have been made. Some of the problems identified included Inadequate capacity to maintain current demand as well as the lack of back up capacity in the event of mechanical and or electrical failure.

With the John Compton Dam as the primary source of supply, recommendations are to increase the output of the current facility to match current and future demands. The proposed solutions to the above stated problems are as follows:

Upgrade of pumping capacity to match future demand (i.e. to the year 2025).

Upgrade of pipework and other civil works

Replacement of the current standby generating set to accommodate for the increased power supply requirements of the larger pump-motor assemblies.

The scope of work required includes the replacement of the the existing pump-motor assemblies, as shown in the photo presented in figure 3.2, No.4 & No.5 (rated at 150 Hp (horsepower) each), with larger capacity pump-motor assemblies (rated at 200 Hp each). The pump-motor assembly unit No.3 is also to be replaced by a 150 Hp unit. This upgrade will facilitate a pumping capacity of approximately 10 MGD as opposed to the existing 6 MGD capacity.

The resulting increase in power supply requirements will require an increase in the standby generating capacity and slight changes to the electrical appurtenances inclusive of the MotorControlCenter to accommodate the increased electrical demand required to sustain at least four pumps in the event of a power loss to the station. These works are planned as upgrades or replacements for existing infrastructure, and fall with the the existing operational design parameters of the system.

This pipeline would be installed parallel to the existing 18” pipeline which would upgrade the raw water transmission pipeline capacity of up to 10 MGD from the Roseau dam and Millet intake.

The joint restraints will be installed on pipe sections between Millet and Vanard stations at river crossings to improve the integrity and reduce the disaster vulnerability of the pipeline particularly when exposed to heavy river flows.

Figure 3.1

Project Area and Generalized Infrastructure

Figure 3.2

Pumps at the John Compton Dam

3.1.2.Expansion of the Theobalds Water Treatment Plant (WTP)

The T.R.Theobalds Water Treatment Plant , or the Ciceron Water Treatment Plant as it was formerly known, was commissioned in March 1993 as part of the upgrade of the general water works that formed part of the Roseau Basin Water Development Project. The components completed under that project included the construction of a 750,000,000 gallon rock filled water dam complete with a pumping station, a new water intake and raw water transmission pipeline at Millet stream extraction station, construction of a 100,000 gallon header tank at Millet, a raw water transmission pipeline between Millet and Ciceron, construction of a modern water treatment plant at Ciceron (T.R.Theobalds ) and finally the first phase installation of a new treated water transmission main from T.R.Theobalds to Port Castries.

The T.R.Theobalds Water Treatment Plant is designed to meet the needs of persons living the northern portions of the island. The areas serviced by this facility plant include all of Castries, the RoseauBasin, Babonneau and Gros Islet and associated rural areas. Demand calculations for the north of the island indicate a current domestic demand (2003) of 5.39 MGD. The demand from the commercial sector such as hotels, cruise ships and other large consumers is an additional 2.5 MGD. This represents a total daily demand of 7.89 MGD.

To date the plant is treating on average a total of 6 MGD. This increase in treatment capacity is in keeping with the maximum design capacity of the plant of 6.5 MGD. Minor modifications have already been made to the plant with respect to the filter media in two of the bays and the use of a coagulant aid – Polymer (PAX-18) for sediment flocculation to improve throughput in the existing facility.

The original design of the system included the installation of a duplicate plant on space reserved at the same site in order to ultimately produce a maximum of 10.0 MGD. This was anticipated to meet the population demands beyond 2005.

Limiting the productivity of the future system however, is the raw water transmission pipeline capacity. New larger pipe (24 inch) was connected to 18 inch lines during the initial project resulting in flow restrictions to the system. The intention was to address replacement of these older lines in the future program phase bringing transmission capacity up the original system design specifications. For the additional treatment capacity to have its desired effect, transmission line upgrades will be required as the available supply will be insufficient to realize the benefit of increased treatment capacity.

Specifically, the expansion of the Theobalds Water Treatment Plant (WTP) will include the following elements:

Expansion of the existing facility –This to meet the capacity of the raw water transmission system which is expected to be approximately 10 MGD.

Modification of receiving chamber - to allow for the increase in flows.

Introduction of plate or tube settlers –to improve the efficiency of the clarifiers by 40% to 50%. The settlers will increase the surface area in the clarifier, thereby reducing the settling time by more then 50%.

Construction of settling tank or pond for the re-cycling of back wash water and sludge collection -a settling tank or pond would be constructed for the treatment of back wash water which is normally discharged with the solids. At an operating volume 9.0 MGD, the total backwash water volume is about 400,000 gallons per back wash cycle. In order to reuse the backwash water it will be necessary to construct a pond to contain this water and to recycle it. With planned improvements to the system, the projected backwash interval when operation at 9.0 MGD is every 2 days.

Trucking of Sludge – the installation of water recovery and sludge drying areas will allow the removal of solids to the Beausejour Sewage Treatment Facility for further processing and drying. Sludges are currently discharged directly to a nearby surface stream.

3.1.3. Upgrade of Morne-Bocage Distribution Line

This component focuses on the Morne, Bocage and Morne Du Don Water Distribution System.

Demand calculations for the north of the island indicate a total daily demand of 7.89 MGD, not including the storage demand, can be expected. Combined supply figures for the Roseau and Hill 20 systems vary between 7.4 MGD and 6.5 MGD during the wet and dry seasons respectively. Domestic demand for the Babonneau region is estimated at 0.7 MGD.

The high elevation areas in the Castries region, (such as Upper Morne Du Don, Bocage, Upper Entrepot and Carillie) are supplied by both the Theobalds and Hill 20 water treatment systems. Hill 20 derives its raw water from two stream extraction stations.. During the rainy season, excess water produced by the Hill 20 System is the primary source of potable water. During the dry season, however the stream flows are greatly reduced and raw water available to the Hill 20 plant is often not capable of supplying the Babonneau region. Under these conditions, water is diverted from the Roseau System to Hill 20. Water is pumped from the Theobalds WTP to Morne via an 8” PVC pipeline. This line flows by gravity to the Bocage reservoir tank through a badly corroded 6” cast iron pipeline.

Current domestic demand (2003) requires a pumping capacity at Theobalds WTP of approximately 1.84 MGD and a gravity line with a capacity of 1.69 MGD. Current capacities for the pumping and gravity system are 0.9 MGD and 0.76 MGD respectively. Table 3.1 summarizes the existing system capacities and present and projected demands.

During the dry season, poor infrastructure and the lack of raw water in the Hill 20 System, dictate that stringent rationing schedules be implemented. Most of the high elevation communities in the Castries and Babonneau areas which enjoy a daily supply during the rainy season, only receive water for a few hours once or twice weekly. This is a rural area and residents most effected include numerous low income families who are unable to purchase storage tanks to compensate for the interruptions in supply.

Table 3.1

Current & Projected Demands (Roseau System & Hill 20 System)

SYSTEM / Existing Capacity (MGD) / Demand 2003*
(MGD) / Demand 2010*
(MGD) / Demand 2015*
(MGD) / Demand
2020* (MGD) / Demand
2025*
(MGD)
ROSEAU SYSTEM
Ciceron P.S.
Morne to Morne

Du Don Pipeline

/ 6.20 (max)
0.90 (max)
0.76 (max) / 7.19
1.84
1.69 / 8.66
2.10
1.93 / 9.92
2.31
2.13 / 11.41
2.53
2.34 / 13.16
2.78
2.57
HILL 20 SYSTEM
Wet Season
Dry Season / 1.20 (max)
0.24 (min) / 0.70 / 0.80 / 0.89 / 0.97 / 1.06
TOTAL
Wet Season
Dry Season / 7.40 (max)
6.44 (min) / 7.89 / 9.46 / 10.81 / 12.38 / 14.22

*Figures do not include demand generated by private storage tanks.

The specific system upgrades to be constructed include the following:

New Ciceron Pump Station at Theobalds WTP - Installation of three duty pumps and one standby pump at Ciceron to meet the estimated water demand of 2.31 MGD by 2015.

New dedicated 12” Pumping Main - Install a 1900m pipeline to improve supply flows from Theobalds WTP to Morne Fortune. Pipeline upgrades are designed to meet water demands estimated at 2.53 MGD in 2020.

New 200,000 Imperial Gallon (Igal) tank at Morne Fortune - Install a 200,000 Igal tank at Morne Fortune to provide additional storage for Flow stabilization during peak demand, Flow stabilization required for firefighting, and Emergency storage.

New 12” gravity main, 4900m - Install a dedicated transmission pipeline directly to existing storage tanks at the Morne and Morne Du Don. This special pipeline link and valve assembly will allow the Theobalds WTP to feed the Bocage Reservoir tank and the Hill 20 WTP.

New 100,000 Imperial gallon (Igal) tank at Babonneau - This storage facility will be required Install a 100,000 Igal tank at Babonneau, near the Hill 20 WTP to accept flows from the Morne. This is to provide additional storage for Flow stabilization during peak demand and flow stabilization required for firefighting, and Emergency storage

3.2. Alternative 2 – Installation of a Mobile Desalination Plant at Pigeon Point (Desal- Plant)