1.4 Measurement of water Quality

Water Quality can be assessed using either physio-chemical data or biological data.

1.4.1 Physio-Chemical Determination of Water Quality.

It is essential in water management to know the concentrations of the various constituents of water. In the most commonly met form of pollution, by organic biodegradable wastes, physio-chemical assessment of water quality is based on five parameters: Biochemical oxygen demand (BOD), Ammonia, Nitrate, Phosphates and dissolved oxygen (Enfo leaflet).

Continuous records of concentration and flow would form the ideal basis for water quality assessment but in practice this is impossible for financial, technical and logistical reasons. Reliance must, therefore, be placed on discrete samples. , The interpretation of data arising from such samples requires great care because these samples constitute only a minute fraction of the whole body of water under investigation and they are only representative of conditions at the particular time of sampling (Lucey et al ,1999).

1.4.2 Biological Determination of Water Quality

Biological monitoring procedures for rivers are based primarily on the examination of suitable resident organisms. The larger and readily visible invertebrate animals which colonise the substrata of all rivers are the most widely used in river quality investigations. These animals are collectively referred to as macroinvertebrates, the main constituents of which are young aquatic stages of certain insects (Enfo leaflet).

Biological water quality assessments by the Environmental protection agency (EPA) are based on macroinvertebrate communities. Organic pollution brings about changes in the macroinvertebrate community and these are well documented. The changes are due to the varying sensitivities of the different components of the community to the stresses caused by pollution. Community diversity declines in the presence of pollution and sensitive species are progressively replaced by more tolerant forms as pollution increases (Lucey et al.,1999).

Observation data may be analysed by biotic or diversity indices or by multivariate technique, the former two methods being the most widely used in the water industry. Several biotic indices have been developed to assess water quality such as the Trent Biotic Index, Chandler Biotic score and Biological Monitoring Working Party (BMWP) Score (Mason, 1996).

Another well known and commonly used Biotic Index is the Q Index of an Foras Forbartha (AFF).

1.4.2.1 Macroinvertebrates as water Quality Indicators.

There are a number of reasons why benthic macroinvertebrates are preferred as water quality indicators:

- The sampling procedures are relatively well developed and can be operated by someone working alone

- There are identification keys for most groups.

- Macroinvertebrates are reasonably sedentary, with comparatively long lives, so that they can be used to assess water quality at a single site over a long period of time.

- They are heterogenous so a single sampling technique may catch a considerable number of species. It is likely, that at least some species or groups will respond to a particular environmental change.

- Macroinvertebrates are generally abundant. (Mason, 1996).

1.5 The Tidy towns Competition

The tidy town has, over the years, developed into one of the most successful voluntary movements in the history of the state.

1.5.1 The History of the Competition.

The tidy towns Competition was inaugurated in 1958 by Board Failte. Over the four decades of its existence it has transformed Irelands towns and villages throughout the country.

In 1995, the Department of the Environment and Local Government took over the running of the competition from Board Failte. From this time, the focus of the competition changed.

Tidy towns is no longer primarily concerned with just the physical appearance of towns and villages, the criteria for adjudication have been broadened to take account the wide range of factors which go to make up the urban and village environment. Tourism is an obvious benefit of doing well in Tidy town, but the main beneficiary is the community itself.

1.5.3 The Categories and marking.

Marks for the Tidy Towns are awarded out of a total of 300. These marks are awarded under six adjudication criteria:

Category	Marks
1. Overall Developmental Approach	50
2. The built Environment, Landscaping and Wildlife	110
(a) The Built Environment	40
(b) Landscaping	40
(c) Wildlife and Natural Amenities	30
3. Litter Control and Tidiness	60
(a) Litter Control	40
(b) Tidiness	20
4. Residential Areas	30
5. Roads, Streets and Back areas	40
6. General Impression	10

Figure 1.5.3.1: Marks awarded in the six categories of the Tidy Towns competition. (Department of the Environment)

This project is mainly concerned with “Wildlife and natural amenities”, which is worth 30 marks.

These marks are broadly awarded for the following:

- Conservation of natural amenities and wildlife areas, e.g. wooded areas, watercourses and adjoining areas, hedgerows.

- Steps taken to encourage wildlife.

- Amenity walks and nature trails.

- Signposting (bilingually, where appropriate) of natural features.

- Appropriate management of access (including access for persons with disabilities) to natural amenities and wildlife areas.

There are a total of six population categories in the tidy towns competition and they range from villages with a population not exceeding 200 to large towns of 10,001 people and over.

Category	Population
A	Not exceeding 200
B	201 – 1,000
C	1,001 – 2,500
D	2,501 – 5,000
E	5,001 – 10,000
F	10,001 and over

Figure 1.5.3.2: Population categories (Department of the Environment).