Carolyn Vanderklauw has written to Telstra seeking a written guarantee the eight-metre mobile tower they plan to erect on Castle Hill RSL Club's roof is safe.
This is a deeply personal crusade for her because in 2005 her older sister Jennifer, then 32, was diagnosed with breast cancer, after 11 years spent sleeping about "100 metres in direct line-of-sight" with a tower. Her sister died at 35.
"I cannot prove the electromagnetic emissions from the antenna caused my sister's breast cancer, however my suspicions that it did are supported by studies," Ms Vanderklauw wrote to Telstra's representative, Aurecon, last week.
"Twenty years later it's the same company threatening my family."
She said if Telstra couldn't provide a guarantee of its latest tower's safety — something her father was denied in 1993 — then she wants it moved at least 500 metres away from Castle Hill High School, which is opposite the RSL club and where she plans to send her four children.
Ms Vanderklauw is among a growing band of angry parents of school-age children and also local scientists — including Dr Pri Bandara and Dr Lisa Stokan — who want Telstra to relocate its proposed telecommunications mast anywhere but near children.
The Department of Education's Mobile Telecommunications Facilities policy (implemented in June 1997) has a "preference" for telecommunications facilities to be built at least 500 metres from a school boundary.
Telstra installs its new infrastructure under the terms of the Mobile Deployment Code "which does not include any distance between schools and mobile-network infrastructure", a spokeswoman said.
FOLLOW THE STORY:
We are now in week six of this campaign.
WHAT DO YOU THINK?
■ Sign the petition: chn.ge/1cFock3
■ Should telecommunications facilities be built near schools and preschools?
■ How good is your mobile coverage in and around Castle Hill RSL? Could it be better?