Disinfection through chlorination is inhibited in turbid water. The turbidity of the raw water passing through the infiltration gallery at the Black Birch can be high, particularly during storms and high turbulence in the stream. During the Easter storms of 2014 the plant became ineffective due to the very high turbidity of the raw water. Filtration is required to improve the turbidity and assist with the treatment for protozoa. 1.5.8 Riverlands Supply and Reticulation The Riverlands water supply was first developed in 1970 to service the Riverlands Industrial Estate east of Blenheim. A well and pumping station were installed at the end of Malthouse Road. Water was taken from the well by surface pumps that operated continuously to meet demand. In the mid 1980s the original well began to fail and a new 200 mm well was installed. In 1997 major development occurred when a 370 m³ reservoir and 920 m of 200-dia pipe were added to the system. Today there is a submersible pump that delivers water at low pressure directly into two surface mounted centrifugal pumps that alternate (duty and standby) to pump water into the reservoir via the reticulation system. The duty pumps are activated by Datran SCADA to start when the reservoir level falls to an adjustable level and stop when the reservoir is full. The water is drawn from a confined aquifer and is not treated or disinfected. A process is underway to establish secure bore water status under the DWSNZ. Adjacent to the Riverlands Industrial Estate is the Cloudy Bay Business Park (CBBP). CBBP is an industrial development of the former Primary Producers Cooperative Society (PPCS) meat processing plant and surrounding land. In 2002 the PPCS plant closed and the privately owned water and wastewater infrastructure was purchased by the Council. This included two bores at Hardings Road and a 4,500 m³ concrete reservoir and associated reticulation. In 2003, 1500 m of 375 mm diameter pipe was laid to connect the CBBP site with the Riverlands Industrial Estate. The Riverlands supply remains primarily for industrial use and the estates are now occupied by several major wineries that have seen very significant growth in recent years. There is a small irrigation system associated with this supply that is not included in this asset management plan. 1.5.9 Wairau Valley Supply and Reticulation The Wairau Valley scheme became operational in 1991. Water is sourced from a bore adjacent to the Wairau River accessed via Keith Coleman Road. Two surface pumps alternate between duty and standby. The water is disinfected with chlorine as it is pumped into the town reticulation. An Akdolit Filtration plant has been installed at the wellhead to raise the pH of the water although this has been bypassed for many years without significant consequences. The supply services an area in the Wairau Valley Township on the northern side of SH 63 from Church Street to Northbank Street only. The scheme was funded from a capital contribution made by residents and a subsidy from the Ministry of Health. Naturally occurring arsenic has been identified in the groundwater to the south of SH 63 which is currently under investigation. The water in this area is very corrosive to metal plumbing. The existing scheme has no spare capacity in its present form to service outside the designated supply district. The reticulation was installed with the development of the scheme and therefore no pipes are greater than 25 years old and all of them are made of PVC. Further details of the water infrastructure are included in Chapter 4: Life Cycle Management Plan, Background Data. Page 11