Penrith City Council’s Recreational Water Monitoring focuses primarily on weekly bacterial testing with monthly physical and chemical parameters being undertaken at four (4) key sites along the Nepean River between October and March each year. Sampling sites include:
- Regatta Park, Emu Plains
- Rowing Club (Nepean River Weir), Penrith
- Devlin Road, Castlereagh.
Tench Reserve - Jamisontown
Regatta Park, Emu Plains
Rowing Club (Nepean River Weir), Penrith
Devlin Road, Castlereagh
About Recreational Water Quality
During the warmer months, you might be tempted to cool off at the Nepean River. But is it safe? Between October and March each year, we test and monitor water quality of the Nepean River for chemical and physical parameters as well as bacteria such as enterococci. While it is not possible to provide real-time water quality results, you can use the map on this page as a general guide to water quality at the following locations:
- Tench Reserve, Jamisontown;
- Regatta Park, Emu Plains;
- Rowing Club (Nepean River Weir), Penrith; and
- Devlin Road, Castlereagh.
Be aware that water quality can change on any given day and contamination can occur at any time, even during dry weather.
What is Recreational Water Monitoring and why we do it.
We all enjoy recreational activities in and around the water, including kayaking, fishing, boating, water sports and other water activities. However, there are potential health hazards associated with using a waterway, which vary depending on the water type and activity.
Council’s Recreational Water Program looks at potential hazards including microbiological and chemical contamination and exposure to algae.
The contamination of recreational waters can result in disease outbreaks and illness in the community. One of the greatest potential risks is posed by microbial contamination of the waters by bacteria, viruses and algae. This is why Council recommends that some water activities be avoided during and for up to three days following rain.
Council has chosen the sampling sites above as we are aware that people use these areas of the River recreationally for a variety of water activities, including swimming and it is hoped that this information will enable our community and visitors to the area to make informed decisions about water quality prior to using the River.
What is enterococci testing?
Enterococci are bacteria that live in the intestinal tracts of warm-blooded animals, including humans and indicate possible contamination of waterways due to faecal waste. Sources of faecal indicator bacteria such as enterococci include wastewater treatment plant effluent, leaking septic systems, stormwater runoff, sewage discharged or dumped from recreational boats, domestic animal and wildlife waste, improper land application of manure or sewage, and runoff from manure storage areas, pastures and feedlots.
Generally, the testing consists of a water sample being filtered through a membrane (which retains the bacteria) and transferred to a selective medium (agar) before being incubated for a period of time at a set temperature.
How do we test water quality?
Council’s Environmental Health Officers collect water samples from each site on a weekly basis from October to March each year. Samples are tested for enterococci, as an indicator of faecal contamination and other physical and chemical parameters are collected monthly in the same period. The enterococci data is used to determine the microbial assessment category, based on a modified 95th percentile. This assessment does not consider the impact of rainfall in the previous two to three days.
Recreational water quality is categorised using a combination of sanitary inspection (identification and rating of potential pollution sources at a site) and microbial water quality assessment. Council has achieved 100 samples for three of the four sites, with Regatta Park having less than the recommended number due to it being a newly added site.
Why do we test water quality?
The sanitary inspection is an assessment of the location’s susceptibility to potential sources of faecal contamination. The overall sanitary inspection considers the risks from all known and potential sources. As some of this information is established on risked based assumptions, this may change as more accurate information becomes available or confirmed, particularly with more details of sewage overflow notifications in the drainage catchments.
How are results assessed?
Results are assessed applying National Health and Medical Research Council (NHMRC) Guidelines for Managing Risk in Recreational Water (NHMRC Guidelines) and provide information on the suitability of sites for recreational use. NHMRC recommend applying NHMRC Guideline values derived for coastal waters, to fresh waters, in the absence of suitable epidemiological studies examining the health risks in freshwater environments for Australian conditions.
With regard to the above, it is important to note that it is not possible to directly derive the microbial assessment categories for freshwater swimming sites on microbial assessment alone due to lack of specific guidelines. There may be differences in the illness rates of seawater swimmers and freshwater swimmers at a given indicator bacterial density, which is likely due to the more rapid die-off of indicator bacteria than of the pathogens in sea water compared to fresh water. As a result, applying the NHMRC Guideline values to sites in the Penrith City Council local government area, where all testing sites are considered to be freshwater, is likely to result in a conservative assessment in relation to the health risk to people using the River.
How to use the map
By hovering over the new map, residents will see an Annual “River Grade” based on both, the microbial water quality assessment undertaken each week combined with the sanitary survey as well as a short-term rating updated each week based on the microbial water quality assessment only.
A Water quality is unlikely to be affected by rain rating suggests the location has generally good microbial water quality.
A Water quality is likely to be affected by recent rain rating suggests the site is susceptible to faecal pollution and bacterial water quality is not always suitable for water activities. Water activities should be avoided during and for up to three days following rain. During dry weather conditions, ensure the location is free from signs of pollution, such as discoloured water, odour or debris in the water.
What is Annual and Weekly grade?
Annual River Grade Ratings
Annual River Grades provide an assessment of water quality over time and are based on a combination of a sanitary survey (identification and rating of potential pollution sources within the catchment) combined with microbial assessment (water sampling gathered over previous years). There are five grades ranging from Very Good to Very Poor:
Very Good: Consistently very good water sampling results and very few potential contamination sources indicate that water quality at this location should be of a very good standard.
Good: Water sampling results are generally good on nearly all occasions and there are few potential faecal pollution sources identified. Standard advisories should be followed such as avoiding contact with water generally for 3 days after rainfall.
Fair: Water sampling results may show times of elevated bacteria mostly due to faecal sources (e.g. bird faeces, sewage overflows) and rainfall. Contact with the water should be avoided during periods of high rainfall events, and if the water is discoloured. Extra care should be taken to avoid contact during and for up to three days following rainfall or if there are signs of pollution such as discoloured water or odour or debris in the water.
Poor: Location is susceptible to faecal pollution and microbial water quality is not always suitable for contact. During dry weather conditions, ensure that the location is free of signs of pollution, such as discoloured water, odour or debris in the water, and avoid contact at all times during and for up to three days following rainfall.
Very Poor: Location is very susceptible to faecal pollution and microbial water quality may often be unsuitable for contact. It is generally recommended to avoid contact with the water at these sites almost all of the time.
Weekly River Grade Ratings
Weekly grade is: this is the weekly rating and provides regular updates of the water quality based only on microbial testing of the River in the weekly period. There are four ratings ranging from Category A to Category D:
Here are some quick tips for you to consider before you go:
- Avoid contact with water for up to three days following rain
- Avoid water with broken skin such as cuts, bites or grazes
- Remember that the very young and old are at greater risk of illness due to contact with poor water quality
- if you do decide to swim in the River, you should be aware of the conditions, enter the water slowly, never dive in or jump from heights, never swim alone and ideally wear a lifejacket