RECOMMENDATION

THAT the minutes of the meeting of the Water and Wastewater Consultative Committee held on Tuesday 6 March 2001 be taken as read and confirmed.

Attached is a report prepared by Bruce Wallace Partners Ltd (BWPL) that compares the options of Jetflote and Land Irrigation. The recommendation contained within that report are for guidance only.

The existing discharge consent for the Waihi oxidation ponds expires in 2004. The current discharge exceeds the consented volumes by a factor of two. Council has been aware of the non-compliance and since 1995 has been endeavouring to find a suitable treatment process upon which a new consent can be based. Whilst reductions in BoD, suspended solids and faecal coliform concentrations were relatively easy to achieve, Environment Waikato also desired a reduction in phosphorous concentrations.

Until several years ago the only practical means of achieving reductions of phosphorous concentrations in oxidation pond effluent was to land dispose the effluent. Over the last 10 years there has been considerable research into land disposal of effluent and a scheme can be developed with a high degree of certainty that it will achieve the desired outcomes. Two major limitations are finding suitable land in the right location at a realistic price, and the dairy industry reluctance to permit the use of silage produced from land used for human effluent disposal for use as a food supplement.

Over the last 3 years a propriety process known as Jetflote has been developed, and is now successfully being used in Australia for phosphorous reduction.

As yet there is no full scale Jetflote processes in New Zealand. Being a relatively new process, there are still improvements being developed, especially in the area of disposal of the residuals.

The concept for the Jetflote process is detailed on page 12, Figure 3 in the BWPL report. That is the treated effluent is pumped up to the Jetflote process, after the Jetflote, the effluent is treated with UV to reduce the bacterial count, then flowed through a landscaped cascade before discharge to the river. At this stage the landscaped cascade is envisaged to be a series of tree and shrub lined of pools and small waterfalls followed by a small natural wetland before discharge into the Ohinemuri River.

BWPL estimate the land treatment and disposal option to have a capital cost of $4.0 million and annual operating cost of $176,300. The Jetflote option to have a capital cost of $1.8 million and annual operating costs of $194,900. Of the two the Jetflote has the lowest Present Day Cost (long term cost).

The current annual operating cost for the Waihi oxidation ponds is $33,500. At the time the annual plan was produced this was projected to increase to $189,000 for a new process. $1.5 million was budgeted in 2002/03 to undertake the capital works.

The renewal of the Waihi sewage treatment plant discharge consents has been a long drawn out process. Over the years there have been public meeting, workshops and reasonable coverage in the local papers. To assist with this consultation process, it is recommended one further information day be held in Waihi where interest groups and members of the public can discuss the issues with Council staff or representatives. Should an interest group request a special meeting to discuss issues relating to the Waihi sewage treatment plant, and then the appropriate people can also attend that.

RECOMMENDATIONS

1. That the Bruce Wallace Partners Report detailing a Comparison of Jetflote and Land Irrigation Options be received.

2. That a Jetlote type treatment process be the preferred means of improving the effluent quality from the Waihi effluent ponds.

3. That interest groups and member of the public be invited to an information day held in Waihi to detail the proposed improvements in the sewage treatment process.

4. That work commences on preparing resource consents application based on the Jetflote proposal as detailed in the Bruce Wallace Partners Ltd report dated February 2000.

· Pump to Ngatea – Awaiting Consultants Report

· Meeting with School 29/3/01 – Verbal update at meeting.

The consultants report has been received. The report recommended further testing of several bores to permit a more conclusive decision to be made. Those tests are currently being undertaken.

Eleven consents based on the concepts previously discussed will be lodge with Environment Waikato by the end of March. Once lodged they will follow due process and any issues raised will have to be dealt with.

Discharge of the residuals (filter and clarifier backwash) from the Kerepehi Water Treatment Plant is being discharged direct to the Awaiti Canal via a pipeline owned by Tanners Sawmills. The discharge consent for the pipeline belongs to Tanners Sawmills. The suspended solid concentration of the backwash water is preventing Tanners Sawmills from renewing their discharge consent. Council has investigated several options for the treatment of these residuals and in the last year has purchased a small farm to the northern side of the Kerepehi water treatment plant with the view of constructing ponds to remove the suspended solids from the backwash. Attached is a plan detailing the proposed layout of the settling ponds. It is proposed to discharge the supernatant from the ponds into the land drainage system that runs along Kerepehi Town Rd/ Wharepoa Rd back to the Waihou River. This is a gravity drain that does not go through a pump and returns the water to the same river as it came from. The other option would be to discharge to the north of the property into another land drainage system, that is at times pumped into the Piako River.

Investigations into the composition of water treatment plant residuals have found them to be relatively inert with a low plant nutritional value.

The volume of supernatant discharged will vary depending on water treatment production and the quality of the raw water being treated. Based on a maximum production through the water treatment plant of 12,500 m3/day (current maximum 6,500m3/day) the maximum daily discharge of supernatant would be 550 m3/day with the average of 396 m3/day.

Feed back on appropriate consultation is sort from this Committee.

David Spiers from Environment Waikato has been invited to present the findings of recent research into the migration and breeding cycle of the fresh water fish species found within the Districts water ways.

The findings are likely to have a significant impact on existing and future structures in waterways. These structures include, farm and road culverts, fords, land drainage floodgates, weirs and dams.