Ezousas artificial groundwater recharge of treated effluent in Cyprus

General

National Id:

Cyprus_01

Site name:

Ezousas riverbed aquifer (Paphos)

Summary:

The coastal part of the Ezousa riverbed aquifer, stretches up to 8 km from the coasts of Pafos district. The measure implementation concern the utilization of the local aquifer as a natural reservoir for natural filtration, storage and reuse of water, by creating and feeding infiltration ponds located in the riverbed. The water consists of tertiary treated sewage originating from the Paphos sewage treatment plant.

NUTS Code:

Κύπρος (Kýpros)

RBD code:

CY001

Transboundary:

Data provider:

Ayis Iacovides, I.A.CO

Source(s):

Attenuation capacity of a coastal aquifer under managed recharge by reclaimed wastewater

Characterization of the Ezousas aquifer of SW Cyprus for storage recovery purposes using treated sewage effluent

NWRM(s) implemented in the case study:

Restoration of natural infiltration to groundwater

Longitude:

32.51429

Latitude:

34.762277

Site information

Climate zone:

warm temperate dry

Mean rainfall:

500

Mean rainfall unit:

mm/year

Average temperature:

18,7000007629395

Mean evaportranspiration:

1060

Mean evaportranspiration unit:

mm/year

Mean runoff:

Mean runoff unit:

450 - 600 mm

Average runoff coefficient:

0,180000007152557

Average imperviousness:

Type:

Case Study Info

Light or indepth?:

Light

Average slope range:

1.0

Vegetation class:

Unvegetaded riverbed

Monitoring maintenance

Monitoring impacts effects:

Monitoring location:

Laboratory

Monitoring parameters:

EC, Boron, pH, P-total: monthly; biochemicals, heavy metals and persistent organic compounds: every three months

Monitoring upstream station:

The sampling data for these analyses are obtained from eight locations: the entry to the infiltration basins, the six abstraction boreholes, and one observation borehole upstream of the recharge site for the native groundwater.

Monitoring downstream station:

Performance

Performance impact estimation method:

Catchment outlet

Performance impact estimation information:

A three-dimensional finite element model of the area was constructed using the FEFLOW software to simulate the groundwater flow conditions and transport of Phosphorous and copper in the subsurface from the recharge process. The model was calibrated using hydraulic head and chemical data for the time period of 2002-2011. The groundwater model was coupled with a geochemical model PHREEQC attempting to evaluate nitrate and Copper processes. Inverse modeling calculation was used to determine sets of moles transfers of phases that are attributed to the water composition change in groundwater between the mixture of natural groundwater and reclaimed wastewater and the final water composition. From the flow model it is suggested that artificial recharge can compensate the lack of upstream recharge only to a point. Thus, a water deficit could potentially be created that will induce the saltwater intrusion phenomenon in the costal area. The general behavior of phosphorus and Copper was captured relatively well with some exceptions.

Biophysical impacts

Retained water:

12000

Retained water unit:

m3/day

Information on retained water:

The Ezousa Recharge Project (ERPr.) is designed to supplement the aquifer with 9000-12000 m3 /day of treated wastewater effluent from Paphos.

Increased water storage:

12000

Increased water storage unit:

m3/day

Information on increased water storage:

The runoff reduction is nil since treated effluent is brought into the riverbed as an additional quantity of water.

Runoff reduction unit:

% Percent

Information on runoff reduction:

The runoff reduction is nil since treated effluent is brought into the riverbed as an additional quantity of water.

Water quality overall improvements:

Positive impact-WQ improvement

Information on Water quality overall improvements:

Weak nitrate dilution is observed. Total Phosphorous is strongly absorbed and attenuated into the aquifer matrix. Higher values of heavy metals, compared to the recharging reclaimed water are observed. Sea intrusion is controlled only up to a point.

Soil quality overall soil improvements:

Not relevant for this application

Information on Soil quality overall soil improvements:

The application of this NWRM does not affect in any way the soil quality except within the ponds themselves.

Lessons, risks, implications...

Key lessons:

The coastal part of the Ezousas riverbed aquifer, up to 8 km from the coast, is utilized as a natural reservoir for storage and reuse of the tertiary treated sewage from Paphos Town. Tertiary treated water recharges the aquifer through specially constructed shallow ponds. The water after natural purification is pumped again from the aquifer for irrigation purposes. At the same time protection from and control of sea-intrusion is accomplished . The key lessons learned are: - Artificial recharge with effluent water can be applied in areas with similar geological conditions experiencing droughts and lack of water. - Conjunctive use of surface and groundwater maximizes the use of available water resources of an area. †¢ Equal quantities of fresh water for domestic use can be saved by recharging treated effluent and effecting additional treatment which are used then for irrigation. †¢ Control of sea intrusion is effectively accomplished.

Financing mechanism:

Financing mechanism information:

In the new water pricing to be implemmented, the irrigation water (fresh or recycled) carries an environmental cost.

Success factor(s):

Type	Role	Comments
Existing staff and consultant knowledge	main factor	Previous experience with succesful Artificial recharge in riverbed with fresh water.

Financing:

Type	Comments
National funds

Barrier:

Type	Role	Comments
Attitude of the public	main barrier	Especially if aquifer to be recharged with treated effluent serves also domestic supply.

Driver:

Type	Role	Comments
Organisation committed to it	main driver	WDD is responsible for water resources management in the island.

Financing share:

Share type	Share	Comments
National funds	100

Socio-economic

Direct benefits information:

Pumped water is sold at the price of untreated freshwater.

Costs investment:

4000000

Costs investment information:

Tertiary treatment plant, pumping installation and pipe transfer of treated effluent to the NWRM had a capital cost of 3.9 million euros. On this some 0.1 million euros are added for ponds, boreholes and pumps. These latter figures are to be verified.

Costs operational information:

Monitoring staff and operation supervising.

Costs maintenance information:

Maintenance of structures after occasional flooding. Renovation of infiltration capacity.Servicing of pumps.

Costs total:

4000000

Costs total information:

Includes ponds (shallow earth walls structures) with simple concrete inlets and outlets. Drilling of wells equipped with pumps, pipes for water transport, monitoring equipment (water levels/meters and quality probes). Staff to monitor and run the NWRM.

Ecosystem improved biodiversity:

Information on Ecosystem improved biodiversity:

Construction of ponds has overtaken permanently part of habitats. No serious impacts expected on flora although construction works destroyed parts of flora population. Minor impacts on fauna are expected since works overtake parts of riparian habitats.

Ecosystem provisioning services:

Information on Ecosystem provisioning services:

The site taken by the NWRM is the Esousa main watercourse.

Ecosystem impact climate regulation:

Not relevant for the specific application

Information on Ecosystem impact climate regulation:

The application in its form does not affect in anyway climate change.

Ecosystem erosion control:

Information on Ecosystem erosion control:

The existence of 23 ponds with low retaining walls prevents erosion.

Policy, general governance and design targets

Policy description:

Aquifer recharge and retrieval of sufficient water quantities of acceptable quality for irrigation purposes. Additionally water purification is achieved and sea intrusion is restricted.

Quantified objectives:

3000000m3/yr is recharged into the marginal aquifer.

Part of wider plan:

Policy pressure:

Policy requirement directive:

Policy impact:

Policy wider plan:

Wider plan type	Wider plan focus	Name	Comments
		Reuse of treated water effluent and improvement of aquifer status

Policy area:

Policy target:

Target purpose
Groundwater Recharge
Pollutants Removal
Oher Societal Benefits

Design & implementations

Application scale:

River

Installation date:

2004-01

Performance timescale:

< 1 year

Area (ha):

14500

Area subject to Land use change or Management/Practice change (ha):

4,6100001335144

Size:

46000

Size unit:

Design capacity description:

4200000m3/yr is is the estimated effective storage capacity of the aquifer

Max water retention capacity:

12000

Max water retention capacity unit:

m3/day

Runoff treatment capacity:

260

Runoff treatment capacity unit:

mm/day

Basis of design:

Storage of tertiary treated water in periods of low agricultural water demand.

Constraints:

Aquifer not used for domestic water. Permeable lithologyin unconfined aquifer with sufficient storage availability.

Favourable preconditions:

Aquifer previous lithology, sufficient storativity of aquifer, proximity to a STP or availability of treated effluent.

Management change from:

No Change

Management change to:

No Change

Inflow volume:

156

Inflow volume unit:

m3/month

Contractural arrangements:

Design contractual arrangement:

Design consultation activity:

Design land use change:

Land use change type
Beaches, dunes, sands

Design authority:

Authority type	Role	Responsibility	Name	Comments
Other	Implementation		Sewrage Board of Paphos
National water authority	Implementation		Water Development Department

Last updated: 12 Jan 2015 | Top

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Ezousas artificial groundwater recharge of treated effluent in Cyprus

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