Gabriel Novac & Associates Inc. products

The GNA HYDROSLIDE is a proven technique for regulating sewer flows. Flows from as little as 5 l/s (80 gpm) may be regulated using valves with a nominal flow diameter of 200 mm (8 in). The float activated mechanism of the GNA HYDROSLIDE regulator is designed to maintain a constant discharge without the use of external energy sources. The flow area is adjusted to perfectly match any increase or decrease in the upstream water level.

The GNA CSO HYDROBEND bending weir is designed to have the same flow capacity as a standard overflow weir operating under the same maximum design head and weir length, but is designed so that overflow will only occur when the maximum design water level is reached.

Modern canal networks should be operable without expensive storm-water tanks. The relation between price and performance is being taken into consideration more and more. In individual cases a business management analysis is called for. The systems currently available which promise operation without storm-water tanks offer overall solutions in general, which are expensive and which seldom allow for technically independent effective and inexpensive partial installations. It is often underestimated that large constructions are part of such technology, and that their amortization, especially in the case of partial installations, is uncertain. The option of successive expansion is preferable to an ‘all or nothing’ decision.

The self-contained GNA CSO HYDROSELF system has these main features: The gate which holds back the stored water. The float control mechanism for the gate, which is operated by a closed circuit hydraulic system. The system may also be operated using electric controls, if desired, with power usage < 1.0 kW.

The cleaning of storm water retention tanks as well as waste water equalization basins has always been a time consuming and costly endeavor. The need to send maintenance crews into these types of tanks represents a high risk due to the presence of gases which are caused by the settled matter. The need for a simple, efficient and reliable method of cleaning these tanks has always been present but the solution has not. The AUTOFLUSH solids removal device resolves these problems.

A brush screen that removes solids (down to 4 mm) from overflows. A modular construction that makes it easy to install in new structures or retrofit into existing ones. A brush screen that requires no outside energy source to operate. The spilled flow turns a water wheel which in turn powers the brush screen.

Even when CSO’s and SSO’s are equipped with scum boards, considerable quantities of floatables and suspended solids still reach the waters. Sanitary articles, toilette paper and synthetics are left caught in the river bank after heavy rain. The waters are biologically and hydraulically “stressed”.

The HydroScreen arc-screen has been developed to boost the efficiency of existing emergency overflows and designed for a hydraulically high flow rate. To achieve this, innovative arc rake bars with new PE wiper element were developed. The HydroScreen arc-screen is streamed from bottom to top and is usually positioned horizontally before the weir crest. It is modular and can be delivered in various curve radii with corresponding capacity (see selection diagram). Please inquire for intermediate sizes. The curve segments are optimised at about 90° and 120° degrees at a bar spacing between 4 and 6 mm. Once set up readjustment is not necessary.

The GNA CSO HYDROSWITCH is a proven technique for transferring by gravity, highly polluted base flows and wet weather floatables from a sewer at a higher elevation to a receptor system, without hydraulic or electrical controls.

Decelerates the discharge and activates unused storage volume in sewer networks. The Problem: Measures to protect waters are necessary but often expensive. Legislation demands storage basins for the protection of receiving waters such as streams, rivers and lakes. Because of the huge investment costs involved, municipalities are seldom able to build such structures. Action is also called for when the canals in an urban area are overburdened due to new development areas. The removal of sealed surfaces is often not sufficient so that either buffer basins have to be built or whole canal sections replaced to secure the older parts of the urban area.